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Part: CA3277
Category:
Power Management
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-> Linear Voltage Regulators
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Description: Dual 5V Regulator With Serial Data Buffer Interface For Microcontroller Applications
Company: Intersil Corporation
Datasheet: Download CA3277 datasheet File size : 1382 kB
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CA3277
April 1994
Dual 5V Regulator with Serial Data Buffer Interface for Microcontroller Applications
Description
The CA3277 is a Dual 5V Voltage Regulator IC intended for microprocessor and logic controller applications. It is supplied with features that are commonly specified for sequentially controlled shutdown and startup requirements of microcontrollers. Over-voltage shutdown, short circuit current limiting and thermal shutdown features are provided for protection in the harsh environmental applications of industrial and automotive systems. The CA3277 functions are complementary to the needs of microcontroller and memory circuits, providing for sustained memory with a 5V standby output. The Ignition Comparator senses the voltage level at the IGN IN input and provides a 5V logic switched output (supply sourced from OUT1). The Ignition Output, IGN OUT can be used to signal a system microcontroller which can respond with a logic switched output to the CA3277 ENABLE input control for OUT2. The OUT1 +5V Standby Supply of the regulator is normally used as a power supply for microcontroller/memory circuits to preserve stored data when in the standby mode.To allow for maximum heat transfer from the chip, the four center leads are directly connected to the die mounting pad. Refer to AN9302 for further information on CA3277 circuit Applications.
Features
· Dual 5V Regulator - VOUT1 at 5V 100mA - Standby - VOUT2 at 5V 100mA - Enabled - Regulation Range 6V to 18V - Bandgap Voltage References · Low Quiescent Idle Current, 500µA Typ. · Over-Voltage Shutdown Protection, 20.5V Typ. · Reverse Battery Protection, -26V Max. · Thermal Shutdown Protection · Short Circuit Current Limiting · Low Input P.S. Flag and Delayed Reset Control · Low Voltage Shutdown Control, Ouput1 · Ignition Comparator Logic Level Control · Data Comparator and 100X Current Mult. Used as Input/Output Buffers for Remote Serial Data Communication
Applications
· Automotive 5V Regulators and Data Buffers · Industrial Controller Remote System · Microcontroller and Memory Power Supply · Radio, TV, CATV, Consumer Applications
Ordering Information
PART NUMBER CA3277E TEMPERATURE RANGE -40oC to +85oC PACKAGE 16 Lead Plastic DIP
Pinout
CA3277 (PDIP) TOP VIEW
BATT OUT1 DATA IN GND GND DATA OUT CRST RESET 1 2 3 4 5 6 7 8 16 IGN 15 OUT2 14 ENABLE 13 GND 12 GND 11 IGN OUT 10 CUR IN 9 CUR OUT
Functional Block Diagram
1 BATT OVERVOLTAGE SHTDWN LOW VOLTAGE SHTDWN + BANDGAP VOLTAGE REF 1.2V 2 OUT1 +5V (STANDBY)
-
OUT1 REG. DR. CNTRL
+
-
RESET 8 7 CRST 15 OUT2 +5V (ENABLE)
OVERTEMP SHTDWN ENABLE 14 (OUTPUT2)
+
-
OUT2 REG. DR. CNTRL
+
DATA IN 3 IN
+ -
6 DATA OUT
IGN IN
16 + -
11 IGN OUT
10 CUR IN
CURRENT MULTIPLIER
9 CUR OUT 4, 5 AND 12, 13 GND
VBATT -2.9V
6V
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Copyright © Intersil Corporation 1999
File Number
2792.4
7-1
Specifications CA3277
Absolute Maximum Ratings
Max. BATT, IGN IN Input Voltage (Note1) . . . . . . . . . . . . . . . ±26V Max. Operating Voltage; BATT, IGN IN . . . . . . . VBATT(SD) (~20.5V) Max. Positive Voltages: (For Negative Voltages, Note 2) ENABLE Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VBATT DATA IN Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VBATT CUR OUT, Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VBATT RESET, Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VBATT Max. Operating Load Current, OUT1 . . . . . . . . . . . . . . . . . . . 100mA Max. Operating Load Current, OUT2 . . . . . . . . . . . . . . . . . . . 100mA Max. Current Mult. Load Currents: Min. Load Resistance, CUR OUT . . 225 to BATT (75mA max) Min. Load Resistance, CUR IN . . . . . . 1K to GND (-5mA max) Max. Load Current OUT1, OUT2 (Short Duration) . . . Self-Limiting Max. Plus/Minus Load Currents: (Note 3) IGN OUT Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Self-Limiting DATA OUT Output . . . . . . . . . . . . . . . . . . . . . . . . . . .Self-Limiting RESET Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Self-Limiting
Thermal Information
Thermal Resistance JA JL Plastic DIP Package . . . . . . . . . . . . . . . . 60oC/W 12oC/W (Temp. meas. on center lead next to case) Power Dissipation, PD (Note 4): Up to +60oC (Free Air). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5W Above +60oC: . . . . . . . . . . . . . . . . Derate Linearly at 16.6mW/oC Up to +85oC w/heat sink (PC Board): . . . . . . . . . . . . . . . . . 1.6 W Operating Temperature Range . . . . . . . . . . . . . . . . . -40oC to +85oC Storage Temperature Range. . . . . . . . . . . . . . . . . . -55oC to +150oC Max. Junction Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . +150oC Lead Temperature (During Solder) . . . . . . . . . . . . . . . . . . . . +265oC 1/16 ± 1/32" from case, 10s max
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Electrical Specifications TA = -40oC to +85oC, VBATT = 13.5V, ENABLE ON (VEN = 3.5V), IGN IN connected to BATT, OUT1 and
OUT2 bypassed with 20µF to GND, DATA IN connected through 250 to BATT, LOADS: OUT1 = 50mA, OUT2 = 80mA; Unless Otherwise Specified (Refer to Figure 4 Test Circuit) PARAMETERS REGULATOR OUTPUT1 Output Voltage Dropout Voltage (Note 5) Line Reg Load Reg Current Limiting Low Voltage Shutdown REGULATOR OUTPUT2 Output Voltage Dropout Voltage (Note 5) Line Reg Load Reg Current Limiting ENABLE Input Current ENABLE Input Sw. Thd. CURRENT MULTIPLIER Current Mult. Gain, (ICOUT/ICIN) Current Mult. Output Sat. Current Mult., Max. Drive Cur. RESET Reset, (RST) Threshold Reset Delay Time (Note 6) RESET Out High RESET Low RESET Output Sink Current tRST VOH(RST) VOL(RST) IOL Ramp VBATT Down, Measure VBATT when RESET (VRST) goes low CRST Cap. = 0.47µF, VBATT = 6.8V RESET Load = 5K to OUT1 47K to OUT1 VBATT = 3.75V, RST 47K to OUT1 CRST to GND, VBATT = 6.8V 3.8 50 4 4.2 150 8 4.5 250 0.2 V ms V V mA VCOUT(SAT) ICOUT(MAX) ICIN = -200µA ICIN = -200µA, CUR OUT Load = 1K to VBATT ICIN = -700µA 80 35 100 0.3 50 1 Gain Ratio V mA IEN VEN(THD) VEN = 5V Ramp ENABLE Input Up Until OUT2 is Switched ON VOUT2 VDO2 VBATT = 9V to 16V VBATT = 5.6V VBATT = 6.2V to 16V ILOAD = 0.5mA to 80mA 4.75 4.6 5 5 7.5 35 190 50 1.2 5.25 40 60 250 150 V V mV mV mA µA V Ramp VBATT Down Until OUT1 drops (PNP Driver Cutoff) VOUT1 VDO1 VBATT = 9V to 16V VBATT = 4.75V VBATT = 6.2V to 16V ILOAD = 0.5mA to 50mA 4.75 4.15 5 4.6 9 30 170 3.5 5.25 40 60 250 V V mV mV mA V SYMBOL CONDITIONS MIN TYP MAX UNITS
7-2
Specifications CA3277
Electrical Specifications TA = -40oC to +85oC, VBATT = 13.5V, ENABLE ON (VEN = 3.5V), IGN IN connected to BATT, OUT1 and
OUT2 bypassed with 20µF to GND, DATA IN connected through 250 to BATT, LOADS: OUT1 = 50mA, OUT2 = 80mA; Unless Otherwise Specified (Refer to Figure 4 Test Circuit) (Continued) PARAMETERS DATA COMPARATOR Data Comp Thd Data Comp Hysteresis DATA OUT Low DATA OUT High DATA OUT Low Sink Current DATA OUT High Source Current IGNITION COMPARATOR Ign Comp Thd Ign Comp Hysteresis IGN OUT Low IGN OUT High IGN OUT Low Sink Current IGN OUT High Source Current OTHER PARAMETERS Idle Current Over-Voltage Shutdown Thermal Shutdown Ripple Rejection NOTES: 1. For negative voltages on the BATT and IGN IN inputs, current drain is primarily reverse junction leakage, except when DATA IN, CUR OUT, ENABLE and RESET are directly connected to BATT. (Note 2) 2. For negative voltage DATA IN, CUR OUT, ENABLE and RESET interface to NPN or equivalent on-chip structures; providing a forward junction for current conduction into the IC. Negative current must be limited by the impedance of the external connection. This is also the case where these terminals are interconnected to BATT, Normal application does not require the BATT connection, except for DATA IN where a series diode for reverse current blocking may be used. (see Description text information) 3. Refer to the Electrical Characteristic TABLE for all Self-Limiting values. 4. Dissipation, approximately equals: PD [(VINIIN) + (VCUR OUTICUR OUT) - 5(IOUT1+IOUT2)], where IINVIN is IGN IN and BATT input dissipation and VOUT1~VOUT2~5V. This assumes neglibible dissipation for the Ignition Comp., Reset and Data Comp. Outputs. 5. Dropout Voltage is VDO1 = (VBATT - VOUT1) for REG. OUT1 and VDO2 = (VBATT - VOUT2) for REG. OUT2 6. Reset Delay Time, tRST is the time period that the RESET (Pin 8) is low following the discharge of the CRST capacitor to ground. For test evaluation, the CRST pin may be discharged repetitively with a transistor switch. The RESET pin switches from low to high when the CRST pin is charged to approximately 3V. Normal ATE testing measures the source charging current. which is typically 10µA. For any other value of Capacitor the charge time, t for reset is determined as follows: t ~308C, where C is in µF and t is in milliseconds. (i.e. C = 0.47µF, t = 141ms) IQ VBATT(OVSD) TJ 1VPP at 3kHz on BATT INPUT, Measure AC Ripple on OUT1, OUT2 VBATT = 12.6V, No Loads, VEN = VIGN IN = 0V Ramp VBATT Up Until OUT1 and OUT2 Shutdown 19 45 500 20.5 150 55 800 23 µA V
oC
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
VBATT - 3.6 VOL VOH IOL IOH VBATT = 16V, VDATA IN = (VBATT -5V) VBATT = 16V, VDATA IN = 16V VDATA IN Low VDATA IN High VOUT1 -0.15 -
VBATT -2.9 200 1 -50
VBATT -2.2 0.15 5.25 -
V mV V V mA µA
5.5 VOL VOH IOL IOH VIGN IN Low VIGN IN High 4.6 -
6 200 -
6.5 0.15 5.25
V mV V V mA µA
1 -70
-
dB
7-3
CA3277
R1 220 C1 0.1µF L1 150µH UNREG SUPPLY IN 330 6V BATT C2 200µF DATA IN CUR OUT I CURRENT AMP CUR IN R4 22k TO OUT2 +5V DISPLAY OR CONTROL OUTPUT TDO RDI SENSE CONTROL IN OUT RESET VDD +5V CMOS MEMORY VSS DATA IGN EN OUT OUT (OUT2) (VBATT -2.9V) DATA COMP
IGN IN
IGN IN
CA3277 IGNITION COMP
OVR-TEMP SHTDWN OVR-VOLT SHTDWN LOW VOLT
OUT2 C5 0.1µF OUT1 C7 0.1µF C8 100µF C6 22µF
+5V ENABLE SWITCHED OUTPUT
ERROR AMP AND OUTPUT CONTROL
FB
+5V STANDBY OUTPUT
SHTDWN
BANDGAP REF
ERROR AMP AND OUTPUT CONTROL
FB
OUT2 ENABLE
LOW VOLT RESET
CRST GND C3 0.47µF
RESET
R5 47K
C4 0.01µF
5V MICROCONTROLLER
BUS
NOTE:
DATA IN and CUR OUT are remote/host Serial Data Communication Buffers. Typical Remote Source Impedance for DATA IN is 1k. Typical Remote Load for CUR OUT is 250.
FIGURE 1. TYPICAL APPLICATION CIRCUIT OF THE CA3277 DUAL 5V REGULATOR WITH MICROCONTROLLER AND SERIAL DATA BUFFER INTERFACE TO A REMOTE HOST
Applications
Other functions of the CA3277 include a Data Comparator and Current Multiplier for use as interface buffers to transfer serial data at higher level logic to and from a remote host microcontroller. The OUT1 5V Standby Supply provides power to the local microcontroller which interfaces to the CA3277 interface buffers at a 5V logic level. As shown in Figure 1, the DATA IN input of the Data Comparator receives serial data referenced to the BATT voltage level. The output of the Data Comparator is 5V CMOS compatible logic and is connected to the RDI (remote data input) terminal of the microcontroller. The TDO (data out) output of the microcontroller is connected to the Current Multiplier input of the CA3277. Current Multiplier - The Current Multiplier, with internal circuitry shown in Figure 2, receives data from the microcontroller in the form of an open drain or gate switched output driving a 22K resistor load in series to the Current Input at pin 10 (CUR IN). The input stage of the Current Multiplier is a current mirror amplifier which is internally connected to the 5V regulated OUT1 voltage source. The output stage of the Current Multiplier is a current mirror amplifier referenced to GND and has an open collector Current Output at pin 9 (CUR OUT), with a minimum drive capability of 35mA. The Current Multiplier output load is normally connected via resistive loading to the BATT voltage supply level. As such, the microcontroller transmits data out (TDO output) to the input of the CA3277 Current Multiplier which amplifies and translates the signal back to the voltage reference level of the BATT power supply input. When driving a similar remote CA3277, the voltage drop from the BATT input line switches the Data Comparator which provides serial data to the RDI input of the remote microcontroller. The nominal current gain of the Current Multiplier is 100X. The application use of the Current Multiplier is not limited to digital serial data transfer. The Current Multiplier is an independent function and is open to use for other purposes, including linear signal amplification, sensor output amplification and current controlled threshold switching. The current output terminal, CUR OUT may be externally loadconnected to OUT1, OUT2, BATT or any other power supply level up to the maximum ratings given for the BATT input terminal. It is important to note that some applied uses of the Current Multiplier may contribute significant on-chip power dissipation. A nominal current mirror input drive of 200µA will provide sufficient drive to switch a 250 resistor load at the input of the data comparator. As such, the quiescent OFF condition of the Data comparator should be in the High state.
7-4
CA3277
Ignition Comparator - While the Ignition Comparator is provided as an essential part of the start-up control in automotive systems, this circuit function may be used as an independent switching comparator. It is important to note that the thermal shutdown feature on the chip is disabled when the IGN IN input is low. Disabling of the onchip thermal protection is done to satisfy the requirement of low idle current when the system is in a standby condition. The non-inverting IGN IN input has a switching threshold of typically 6V with 200mV of hysteresis and is switched with logic levels reference to GND as the low state and BATT as the high state. The IGN OUT output is 5V CMOS compatible logic, equivalent to the Data Comparator output stage, but is internally supply biased from the Standby 5V Regulator. As such, the high state is level referenced to OUT1. The IGN OUT output terminal can typically sink 1.2mA in a low state or source 70µA in a high state. Enable - A CMOS or TTL high at the ENABLE input switches the regulated 5V/Switched Output ON at OUT2. The ENABLE input has an internal pull-down of typically 50µA to ensure that OUT2 is OFF when the ENABLE input is not connected. The input threshold level for switching is the bandgap voltage reference of 1.2V. When the ENABLE input is low, all drive current to the output pass transistor is cutoff and OUT2 voltage drops to ground level. The ENABLE input is normally switched from the interfacing microcontroller but may be activated from a remote source. Reset - The purpose of the Low Voltage Reset function is to flag a low voltage condition at OUT1. When the RESET output, pin 8 switches low, the voltage level at OUT1 has dropped below the regulation level. The CRST and RESET are high when OUT1 is at 5V. When OUT1 drops to less than 4.2V (typical), the CRST Capacitor at pin 7 is internally discharged, causing the RESET pin to change from a high to a low state, outputting a negative going pulse. The RESET output is an NPN open collector driver requiring an external load resistor, normally connected to OUT1. The RESET output flag may be sent to a microcontroller to initiate a power-down sequence. For any condition that causes OUT1 to drop below the reset threshold, such as undesired transients, the RESET output is switched low for a delay period, tRST determined by the value of the external capacitor, CRST at CRST terminal. For a value of 0.47µF the delay period is typically 141ms. This correlates to approximately 10µA of charging current sourced from the CRST terminal to charge CRST. Regulation - The regulated output stages of the CA3277 have similar circuits, each having an error amplifier to compare the output voltage to the bandgap reference voltage. The circuit of the 5V/Switched regulator is shown in Figure 3. By feedback, the output voltage is differentially compared to the bandgap reference voltage. The error signal is then amplified to drive a PNP pass transistor and maintain a stable 5V output with both line and load regulation over the full operating temperature range. Except for the ENABLE control of OUT2, the OUT1 drive circuit is similar to the OUT2 circuit.
CA3277
INTERNALLY CONNECTED TO OUT1 (+5V)
BATT
250 DI 510 + -
DATA COMP.
Q99 CUR IN 10 5X GAIN
Q100
Q101 Q102 C3 10pF 20X GAIN Q103
CUR OUT 9
CA3277 REMOTE SYSTEM
ICIN GND 4, 5 AND 12, 13
FIGURE 2. CURRENT MULTIPLIER DRIVING A REMOTE CA3277 DATA COMPARATOR
Data Comparator - The Data Comparator provides a means of translating serial data from a high to low voltage. The DATA IN terminal of the Data Comparator is biased to receive signal input that is source referenced to the BATT supply voltage level. In normal use the signal input would be supplied from a remote Current Multiplier having a resistor load tied to the BATT voltage supply. The DATA OUT output from the Data Comparator is CMOS compatible 5V noninverting logic data referenced to GND. The switching threshold at the DATA IN input is bias stabilized by the bandgap voltage and is typically at (VBATT - 2.9V). The Data Comparator is in a high state when DATA IN input is at the BATT voltage level and is in a low state when DATA IN is at (VBATT - 5V). The output stage of the Data Comparator is internally supply biased from the Switched 5V Regulator output to provide a high state of 5V and a low state of 0V (GND). The DATA OUT terminal can typically sink 1.2mA in a low state or source 50µA in a high state. In system applications the Data Comparator is used to translate remote data at high voltage down to 5V logic levels. The Current Multiplier is used to reverse the process by translating 5V logic data back to the BATT voltage level when sending data back to the remote system. The Data Comparator and Current Multiplier are level matched for remote communication between microcontroller systems using the common BATT power supply voltage of the CA3277. The current driven serial data from the Current Multiplier is sent to a remote system by translating the signal up to the BATT voltage level, or an external power supply level that is compatible with the remote device. The Data Comparator of the remote system receives the data, interfaces to its microcontroller and responds with signal drive from its Current Multiplier to translate the signal back to the host. For best noise immunity the transmission in each direction should be over a twisted pair or shielded line. As such, two microcontrollers, each with the interface protection of a CA3277, can provide intelligent master/slave system communications under adverse environmental conditions.
7-5
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