
SLVS262 FEBRUARY 2000
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
High-Speed Output Circuit to Drive PNP
Power Transistor
Precision Reference Voltage . . . 1.5 V
±
2%
at T
A
= 25
°
C
Oscillator Frequency . . . 50 kHz to 0.8 MHz
Low Supply Voltage Operation V
CC
= 2.5 V
to 12 V
Output Voltage Limit (Channel 5 and 6)
Low Supply Current
Internal Undervoltage Lockout Protection
Internal Short-Circuit Protection
Shutdown Function
External Sink Current Setting on Output
Stage
description
The TL1466I is a six channel pulse-width-modulation (PWM) control circuit. This device contains reference
voltage with a precision of
±
2%, a triangle wave oscillator capable of high frequency oscillation up to 0.8 MHz,
various protection circuitry, and shutdown circuitry. The output regulation voltage for each channel is set by an
external resistor divider. Moreover, the output stage is capable of driving a PNP power transistor with high
speed. The high frequency/efficiency switching operation eliminates switching loss by using internal over-drive
circuitry at the rising edge and with reverse bias connecting external bootstrap capacitor at the falling edge. The
MOSFET can be used in parallel with the output diode at channel 1 and 4. This results in further high efficiency
operation replacing the constant time with this MOSFET when the output diode is turned on. Furthermore, it
operates 2.5 V supply voltage and balances switching current by switching repeatedly at the reverse phase with
two pairs (channel 1, 4, 6, and 2, 3, 5) of the six channels. The oscillator output of channel 1, 4, and 6 is reverse
phase for channel 2, 3, and 5. As a result of these features, this device is well-suited for power supply of portable
systems in battery-powered equipment.
FUNCTION TABLE FOR STANDBY
INPUT
OUTPUT
STANDBY
VI
≤
0.4 V
STANDBY-3
X
VI
≥
2 V
VI
≤
0.4 V
VREF
OUTPUT1, 2, 4, 5, 6
OUTPUT3
OFF
OFF
OFF
VI
≥
2 V
ON
ON
ON
ON
ON
OFF
X: High-level or low-level
Copyright
2000, Texas Instruments Incorporated
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.