January 22, 2002 TOKO, Inc.
Page 1
TK740xxL
BLOCK DIAGRAM
TK740xxL
DUAL LOW DROPOUT VOLTAGE REGULATOR
FEATURES
APPLICATIONS
n BatteryPoweredSystems
n MeasurementSystems
n MobileCommunicationsSystems
n CellularPhones
n CordlessPhones
n PDAs
n Toy Motor Drivers
DESCRIPTION
n 2ChannelLDOinonePackage
n OutputscanbesetbyExternalResistors
n High Precision Output Voltage (± 2.0 % or ± 60 mV)
n IndependentActiveHighOn/OffControlforeachLDO
n Very Low Dropout Voltage (V
DROPA = 90 mV at 100 mA,
V
DROPB = 80 mV at 50 mA)
n StablewithCeramicCapacitors
n ExcellentRippleRejectionRatio(84dB@400Hz)
n 1 A at Shutdown
n PeakOutputCurrentis370mA
n SOT23L-8 Package
n WideOperatingVoltageRange(1.8V~14.5V)
n ReverseBiasandOvercurrentProtection
n Built-inThermalShutdown
8
GND
VIN
ON/OFF CONTROL A
VOUTA
VOUTB
FBA
FBB
ON/OFF CONTROL B
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 F
BA 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 A 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
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
mFprovidesstableoperationforV
OUT 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.
GND
BANDGAP
REFERENCE
GND
BANDGAP
REFERENCE
FBA
VIN
VOUT A
VOUT B
FBB
ON / OFF
CONTROL
A
B
THERMAL &
OVER CURRENT
PROTECTION
RIN = 300 k
TK740 CL-
ORDERING INFORMATION
Package Code
PACKAGE CODE:
S: SOT23L-8
VOLTAGE CODES:
Refer to Table 1
Temp. Code
Tape/Reel Code
TEMP. CODE:
C: -30 to 80°C
I: -40 to 85°C
TAPE/REEL CODE:
L: Tape Left
Reel Size = 1300 pcs.
B Side Voltage Code
A Side Voltage Code