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Part: A8285SLB
Category:
Description: LNB Supply And Control Voltage Regulator
Company: Allegro Micro Systems, Inc.
Datasheet: Download A8285SLB datasheet File size : 227 kB
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Datasheet text preview:
Preliminary Data Sheet Subject to Change without Notice January 21, 2004
A8285/A8287
Intended for analog and digital satellite receivers, the LNB (low noise block) converter regulator is a monolithic linear and switching voltage regulator, specifically designed to provide power and interface signals to an LNB downconverter, via coaxial cable. The device uses a 2-wire bidirectional serial interface, compatible with the I2C (Inter-C bus) standard, that operates up to 400 kHz. The A8285 is supplied in a 16-lead plastic power SOIC with copper batwing tabs (suffix LB). The A8287 is supplied in a 24-lead plastic power SOIC with copper batwing tabs (part number suffix LB).
Data Sheet 27448.003c
LNB Supply and Control Voltage Regulator
SCL
1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9
VCP BOOST LX GND LNB TOUT TCAP NC
A8285SlB SOIC
SDA IRQ GND VREG VIN
Scale 1:1
EXTM ADD
SCL
1 2 3 4 5 6 7 8 9 10 11 12
24 23 22 21 20 19 18 17 16 15 14 13
VCP BOOST GND GND LX GND GND LNB TOUT TCAP NC TDI
A8287SlB SOIC
SDA IRQ GND GND GND GND VREG VIN EXTM ADD TDO
Scale 1:1
FEATURES
LNB selection and standby function Provides up to 500 mA load current Two-wire serial I2C interface Built-in tone oscillator, factory-trimmed to 22 kHz; facilitates DiSEqCTM 2.0 encoding Auxiliary modulation input 22 kHz tone detector facilitates DiSEqCTM decoding (A8287 only) Tracking switch-mode power converter for lowest dissipation LNB overcurrent protection and diagnostics Internal overtemperature protection LNB voltages (16 possible levels) compatible with all common standards
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, VIN...16 V Output Current, IOUT ......... Internally Limited* Output Voltage LNB, BOOST ............0.3 V to 28 V TOUT ......... 0.3 V to 22 V Logic Input EXTM ..0.3 V to 5 V Other ... 0.3 V to 7 V Logic Output ....... 0.3 V to 7 V Package Power Dissipation ..See power dissipation information in the Application Information section Operating Temperature Ambient, TA ..... 20°C to +85°C Junction, TJ..... 20°C to +150°C Storage,TS ..... 55°C to +150°C * Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified current rating or a junction temperature of +150°C.
Use the following complete part numbers when ordering:
Part Number A8287SLB A8285SLB Package 24-pin, batwing SOIC 16-pin, batwing SOIC Description All features Tone detect not provided
Data Sheet Preliminary 27448.003c
A8285/A8287 LNB Supply and Control Voltage Regulator
Functional Block Diagram
V IN C10 100 nF C1 33 uF L1 33 uH D1 C5 100 nF C2 100 nF C4 100 uF
VIN VREG C3 220 nF Internal Regulator OSC In Boost Converter
LX
VCP
BOOST
BOOST Feedback
Charge Pump VPUMP Overcurrent
OSC EXTM 100 mV
DISABLE
R1 15 L2 220 uH 220 nF C7 220 nF C6
R3 R4 R5 VDD SDA SCL ADD
Clock Divider
22 kHz Tone Gene rator
LNB
Tracking Regulator
D2 TCAP
I C Interface
2
Output Voltage Select
GM TOUT TDI
6.8 nF C8 220 R2 10 nF C9 R6 TDO VDD
IRQ
Fault Monitor Overcurrent TSD Un dervoltage
Overcurrent
22 kHz Tone Detector
Tone detector and leads TDI and TDO are not provided in 16-pin package (A8285).
ID
C1 C2, C5,C10 C4 C3,C6,C7 C8 C9 R1 R2 R3-R6 L1 L2 D1 D2
Characteristics
33 µF, 25 V, esr 350 mA 100 nF, 50 V, X5R or X7R 100 µF, 35 V, esr 800 mA 220 nF, 50 V, X5R or X7R 6.8 nF, 50 V; Y5V, X5R, or X7R 10 nF (maximum), 50 V; Y5V, X5R, or X7R 15 , 1%, c W 220 , 1%, 2 W Value determined by VDD, bus capacitance. etc. 33 µH, IDC > 1.3 A 220 µH, IDC > 0.5 A 1 A, 35 V or 40 V, Schottky diode 1 A, 100 V, 1N4002
Suggested Manufacturer
Nichicon, part number UHC1E330MET Nichicon, part number UHC1V101MPT
TDK, part number TSL0808-330K1R4; Coilcraft, part number DR0810-333 TDK, part number TSL0808-221KR54; Coilcraft, part number DR0810-224 Various, part number 1N5819; Sanken, part number AW04
www.allegromicro.com
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2
Data Sheet Preliminary 27448.003c
A8285/A8287 LNB Supply and Control Voltage Regulator
ELECTRICAL CHARACTERISTICS at TA = +25°C, VIN = 10 to 16 V (unless otherwise noted)
Characteristics Set-point Accuracy, load and line regulation Supply Current Boost Switch-On Resistance Switching Frequency Switch Current Limit Linear Regulator Voltage Drop Slew Rate Current on TCAP Output Voltage Slew Period Output Reverse Current Ripple and Noise on LNB Output Protection Circuitry Overcurrent Limit Overcurrent Disable Time VIN Undervoltage Threshold VIN Turn-On Threshold Power-Not-Good Flag Set Power-Not-Good Flag Reset Thermal Shutdown Threshold Thermal Shutdown Hysteresis ILIM tDIS UVOFF UVON PNGset High limit Low limit Guaranteed turn-off Guaranteed turn-on 550 400 1.2 8.65 8.75 77 82 700 500 9.15 9.25 85 90 165 20 850 600 1.7 9.65 9.75 93 98 mA mA ms V V %VLNB %VLNB °C °C Symbol VO1 ICC ICCEN Test Conditions Relative to target voltage selected, with: ILOAD = 0 to 500 mA ENB = Low, LNB output disabled ENB = High, LNB output enabled, ILOAD = 0mA Min. -4.5 320 2.0 400 12.5 7.5 Typ. 0 400 352 3 600 10 10 500 1 Max. 4.5 7 15 500 384 4.0 800 7.5 12.5 5 50 Units % mA mA m kHz A mV µA µA µs mA mVpp
RDSBOOST TJ = 25 °C, ILOAD = 500mA fo VREG ICAP tslew IOR VRN VIN = 12 V VBOOST VLNB, no tone signal, ILOAD = 500 mA Charging Discharging VLNB = 13 to 18 V, TCAP = 6.8 nF, ILOAD = 500 mA ENB = Low, VLNB = 28 V with C4 fully charged See notes 1 and 2
PNGreset TJ TJ See note 1 See note 1
Continued on next page
www.allegromicro.com
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
3
Data Sheet Preliminary 27448.003c
A8285/A8287 LNB Supply and Control Voltage Regulator
ELECTRICAL CHARACTERISTICS (continued) at TA = +25°C, VIN = 10 to 16 V (unless otherwise noted)
Characteristics
Tone Characteristics
Symbol fTONE ITONE tDEL VIH VIL IIL VTDI fTDI ZTDI VOL IOL VIL VIH VHYS IIN VOL IOL fCLK tOF tBUF tHD:STA tSU:STA tLOW tHIGH tSU:DAT tHD:DAT tSU:STO
Test Conditions
Min. 20 30 2 1 260 17.6
Typ. 22 40 8.6
Max. 24 50 1 0.8 1 1000 26.4 0.4 10
Units kHz mA µs V V µA mV kHz k V µA
Tone Frequency Tone Pull-Down Current Tone Turn-On and Turn-Off Delays External Tone Logic Input Input Leakage Tone Detector Input Amplitude Tone Detector Frequency Capture Tone Detector Input Impedance Tone Detector Output Voltage Tone Detector Output Leakage I C Interface
2
Using EXTM pin fIN = 22 kHz 600 mVpp sinewave See note 1 Tone present, ILOAD = 3 mA Tone absent, VO = 7 V VIN = 0 V to 7 V ILOAD = 3 mA VO = 0 V to 7 V VIH to VIL See I2C Interface Timing Diagram See I2C Interface Timing Diagram See I2C Interface Timing Diagram See I C Interface Timing Diagram
2 2
Logic Input (SDA,SCL) Low Level Logic Input (SDA,SCL) High Level Input Hysteresis Logic Input Current Output Voltage (SDA, IRQ) Output Leakage (SDA, IRQ) SCL Clock Frequency Output Fall Time Bus Free Time Between Stop and Start Hold Time for Start Condition Setup Time for Start Condition SCL Low Time SCL High Time Data Setup Time Data Hold Time Setup Time for Stop Condition
2 10 0 1.3 0.6 0.6 1.3 0.6 100 0 0.6
150 <±1.0
0.8 10 0.4 10 400 250 900
V V mV µA V µA kHz ns µs µs µs µs µs ns ns µs
See I C Interface Timing Diagram See note1; I C Interface Timing Diagram
2
See I C Interface Timing Diagram
2 2
See I C Interface Timing Diagram
Continued on next page
www.allegromicro.com
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
4
Data Sheet Preliminary 27448.003c
A8285/A8287 LNB Supply and Control Voltage Regulator
ELECTRICAL CHARACTERISTICS (continued) at TA = +25°C, VIN = 10 to 16 V (unless otherwise noted)
Characteristics I2C Address Setting ADD Voltage for Address 0001,000 ADD Voltage for Address 0001,001 ADD Voltage for Address 0001,010 ADD Voltage for Address 0001,011
Address1 Address2 Address3 Address4
Symbol
Test Conditions
Min. 0 1.3 2.3 3.3
Typ.
Max. 0.7 1.7 2.7 5
Units V V V V
1 Guaranteed by design. 2 Use recommended components and adhere to layout guidelines.
I2C Interface Timing Diagram
tSU:STA tHD:STA tSU:DAT tHD:DAT tSU:STO tBUF
SDA SCL
tLOW
tHIGH
www.allegromicro.com
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
5
Others parts begin by a8
A8-1 A8-2
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