|
|
Part: TC120503EHA
Category:
Power Management
-> Regulators
-> Switching Regulators
Description: TC120 is a 300 KHZ Pfm/pwm Step-down (Buck) DC/DC Regulator/controller Combination For Use in Systems Operating From Two or More Cells, or in Line-powered Applications
Company: Microchip Technology, Inc.
Datasheet: Download TC120503EHA datasheet File size : 162 kB
Request For quote: Find where to buy TC120503EHA
Datasheet text preview:
TC120
PWM/PFM Step-Down Combination Regulator/Controller
Features
· Internal Switching Transistor Supports 600mA Output Current · External Switching Transistor C ontrol for Output Currents of 2A+ · 300kHz Oscillator Frequency Supports Sm all Inductor Size · Short C ircuit Protection · Built-In Undervoltage Lockout · 95% Typical Efficiency · Automatic Sw itchover to Current-Saving PFM Mode at Low O utput Loads · Automatic O utput Capacitor Discharge While in Shutdown · Programmable Soft-Start · Power-Saving Shutdown M ode · Small 8-Pin SO P Package
Package Type
8-Pin SOP
VIN 1 EXTW 2 CPC 3 SHDN/SS 4 8 LX EXT GND SENSE
TC120
7 6 5
General Description
TC120 is a 300kHz PFM/PWM step-down (Buck) DC/ DC regulator/controller com bination for use in systems operating from two or more cells, or in line-powered applications. It uses PWM as the prim ary modulation scheme, but automatically converts to PFM at low output loads for greater efficiency. It requires only an external inductor, Schottky diode, and tw o capacitors to im plement a step-down converter having a maximum output current of 600mA (VIN = 5V, VOUT = 3.3V). An external switching transistor (P-channel M OSFET) can be added to increase output current capability to support output loads of 2A or m ore. The TC120 consumes only 55µA (max) of supply current (VOUT = 3.3V) and can be placed in shutdown mode by bringing the shutdown input (SHDN) low. During shutdown, the regulator is disabled, supply current is reduced to 2.5µA (max), and VOUT is internally pulled to ground, discharging the output capacitor. Norm al operation resumes when SHDN is brought high. Other features include a built-in undervoltage lockout (UVLO), an externally programmable soft start time, and output short circuit protection. The TC120 operates from a maxim um input voltage of 10V and is available in a low-profile 8-Pin SOP package.
Applications
· · · · · · Portable Test Equipment Local Logic Supplies Portable Audio Systems Portable Scanners Palmtops Electronic O rganizers
Device Selection Table
Part Number TC120503EHA TC120333EHA TC120303EHA Output Voltage (V) 5.0 3.3 3.0 Package Operating Temp. Range
8-Pin SOP -40°C to +85°C 8-Pin SOP -40°C to +85°C 8-Pin SOP -40°C to +85°C
Functional Block Diagram
VIN VIN CIN EXTW EXT LX D1 COUT L1 VOUT
TC120XX03
CPC GND
SHDN/SS CSS 4.7nF
SENSE
2002 Microchip Technology Inc.
D S21365B-page 1
©
TC120
1 .0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings*
Power Supply Voltage (VIN)........... -0.3V to +12V Voltage on VOUT Pin ....... -0.3V to +12V Voltage on LX, Boost Pins .. (VIN 12V) to (VIN + 0.3V) Voltage on EXT1, EXT2, SHDN Pins ......... (-0.3V) to (VIN + 0.3V) LX Pin Current .... 700mA pk EXT1, EXT2 Pin Current .. ±50mA Continuous Power Dissipation ....... 300mW Operating Temperature Range .... -40°C to +85°C Storage Temperature Range ..... -40°C to +150°C
*Stresses above those listed under "A bsolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. E xposur e to Absolute Maximum Rating conditions for extended periods may affect device reliability.
TC120 ELECTRICAL SPECIFICA TIONS
Electrical Characterist ics: Test circuit of Figure 3-1, TA = 25°C, VIN = VR x 1.2, Note 1 unless otherwise noted. Symbol VOUT Parameter Output Voltage Min Typ Max Units V Test Conditions VOUT = 3.0V IOU T = 120mA (Note 1) VOUT = 3.3V IOU T = 132mA VOUT = 5.0V IOU T = 200mA VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V VOUT = 3.0V VIN = VR x 1.05, no load VOUT = 3.3V VOUT = 5.0V No load, S HDN = 0V, (Note 2) Measured at E XT1 Pin ( Note 2) No load, S HDN = 0V VOUT = 3.0V VOUT = VR x 0.9 (Note 2) VOUT = 3.3V VLX = VIN 0.2V, 10 VOUT = 5.0V Resistor from LX to VIN, S HDN = VIN VOUT = 3.0V S HDN = VIH; EXT1 and EXT2 VOUT = 3.3V connected to 200 load, VOUT = 5.0V VEXT1 = VEXT2 = (VIN 0.4V); VOUT = VIN (Note 2) VOUT = 3.0V S HDN = VIH; EXT1 and EXT2 VOUT = 3.3V pulled up through a series VOUT = 5.0V resistance of 200 to a voltage such that VEXT1, 2 = 0.4V Measured at E XT1 Pin, VIN = VOUT + 0.3V, IOUT = 20mA (Note 3) No load VIN > VR x 1.2
VR x 0.975 VR ± 0.5% VR x 1.025
VIN
Input Voltage
1.8 500 600 600 --
-- -- -- -- 52 55 71 1.5 -- 1.5 0.69 0.64 0.44 38 35 24 31 29 20 300
10.0 -- -- -- 82 86 110 2.5 2 2.5 0.94 0.85 0.58 52 47 32 41 37 26 345
V mA
IOUTMAX Maximum Output C urrent
IIN
Supply Current
µA
ISHDN ILX
Shutdown Supply Current LX Pin Leakage Current
-- -- -- -- -- -- -- -- -- -- -- -- 255
µA µA
RDSON(L LX Pin ON Resistance X)
REXT H
EXT1, E XT2 On Resistance to VIN
REXT L
EXT1, E XT2 On Resistance to GND
fOSC
Oscillator Frequency
k Hz
DPWM DPFM
Note 1: 2: 3:
Maximum PWM Duty Cycle PFM Duty Cycle Efficiency
-- 15 --
-- 25 95
100 35 --
% % %
VR is th e factory-programmed ou tput voltage se tting . No external co mpone nts connected, except C SS. While operating in PWM Mo de.
©
DS 21365B-page 2
2002 Microchip Technology Inc.
TC120
Electrical Characterist ics: Test circuit of Figure 3-1, TA = 25°C, VIN = VR x 1.2, Note 1 unless otherwise noted. Symbol VUVLO Parameter Minimum Operating Voltage Min 0.9 Typ -- Max 1.8 Units V Test Conditions VOUT = VR x 0.9 (N ote 2) , SHDN = VIN Measured with internal transistor in OFF state and VIN falling VOUT = 0V, (Note 2) VOUT = 0V, (Note 2) Time from VOU T = 0V to SHDN = VIL (Note 2)
VIH VIL tPRO tSS
Note 1: 2: 3:
SHDN Input Logic H igh, Thr eshold Voltage SHDN Input Logic Low, Thr eshold Voltage Short C ircuit Protection Response Time Soft Start Time
0.65 -- 3 6
-- -- 5 10
-- 0.20 8 16
V V msec msec
VR is th e factory-programmed ou tput voltage se tting . No external co mpone nts connected, except C SS. While operating in PWM Mo de.
2002 Microchip Technology Inc.
D S21365B-page 3
©
Others parts begin by tc
TC-1 TC-2 TC-3 TC-4 TC-5 TC-6 TC-7 TC-8 TC-9 TC-10 TC-11 TC-12 TC-13 TC-14 TC-15 TC-16 TC-17 TC-18 TC-19 TC-20 TC-21 TC-22 TC-23 TC-24 TC-25 TC-26 TC-27 TC-28 TC-29 TC-30 TC-31 TC-32 TC-33 TC-34 TC-35 TC-36 TC-37 TC-38 TC-39 TC-40 TC-41 TC-42 TC-43 TC-44 TC-45 TC-46
|
|
|
