Document
TK740xxL
DUAL LOW DROPOUT VOLTAGE REGULATOR
FEATURES
n 2 Channel LDO in one Package n Outputs can be set by External Resistors n High Precision Output Voltage (± 2.0 % or ± 60 mV) n Independent Active High On/Off Control for each LDO n Very Low Dropout Voltage (VDROPA = 90 mV at 100 mA,
VDROPB = 80 mV at 50 mA)
n StablewithCeramicCapacitors n Excellent Ripple Rejection Ratio (84 dB @ 400 Hz) n 1 µA at Shutdown n Peak Output Current is 370 mA n SOT23L-8 Package n Wide Operating Voltage Range (1.8 V ~ 14.5 V) n ReverseBiasandOvercurrentProtection n Built-in Thermal Shutdown
DESCRIPTION
The TK740xx is a Dual Ultra Low-Drop-Out regulator with a built-in electronic switch. The A-Side delivers up to 200 mA output current and the B-Side delivers up to 120 mA output current over the full temperature range. The internal switch can be controlled by TTL or CMOS logic levels. The device is in the “on” state when the control pin is pulled to a logic high level. External capacitors can be connected between the FBA and VOUTA and FBB and VOUTB pins to lower the output noise level.
Internal PNP pass transistors are used to achieve a low dropout voltage of 90 mV (typ.) at 100 mA load current side A and 80 mV (typ.) at 50 mA load current side B. The TK740xx has very low quiescent current. 45 µA at no load and 0.4 mA with a 50 mA load. The internal thermal shut down circuitry limits the junction temperature to 150 °C. The
ORDERING INFORMATION
TK740 CL-
Package Code Temp. Code
B Side Voltage Code A Side Voltage Code Tape/Reel Code
VOLTAGE CODES:
Refer to Table 1
PACKAGE CODE:
S: SOT23L-8
TAPE/REEL CODE:
L: Tape Left Reel Size = 1300 pcs.
TEMP. CODE:
C: -30 to 80°C I: -40 to 85°C
APPLICATIONS
n Battery Powered Systems n Measurement Systems n Mobile Communications Systems n Cellular Phones n Cordless Phones n PDAs n Toy Motor Drivers
load current is internally monitored and the device will shut down in the presence of a short circuit or overcurrent condition at the output.
The TK740xx circuit features very high stability. An output capacitor of 0.22 mF provides stable operation for VOUT ³ 2.0 V. Any type of capacitor can be used; however, the larger this capacitor is, the better the overall characteristics are. The ripple rejection ratio is 84 dB at 400 Hz, and 80 dB at 1 kHz.
The TK740xx is available in the SOT23L-8 surface mount package.
TK740xxL
FBA VOUTA VOUTB
FBB
8 ON/OFF CONTROL A VIN GND ON/OFF CONTROL B
VOUT A FBA
BLOCK DIAGRAM
VIN
BANDGAP REFERENCE
GND
ON / OFF CONTROL
AB
RIN = 300 kΩ
THERMAL & OVER CURRENT
PROTECTION
BANDGAP REFERENCE
GND
VOUT B FBB
January 22, 2002 TOKO, Inc.
Page 1
TK740xxL
ABSOLUTE MAXIMUM RATINGS - C RANK
Supply Voltage ............................................... -0.4 to16 V Operating Temperature Range ..................... -30 to +80 °C
Power Dissipation .............................................. 600 mW Noise Bypass Pin Voltage .............................. -0.4 to 5 V
Reverse Bias Voltage ...............