BICMOS PWM CONTROLLERS
TC25C25
TC35C25
PIN CONFIGURATION
(DIP AND SOIC)
IN–
IN+
SYNC
OSC OUT
CT
RT
DISCHARGE
SOFT START
1
2
3
4
5
6
7
8
TC25C25EPE
TC35C25CPE
16
15
14
13
12
11
10
9
VREF
+
VIN
OUTPUT B
VDD
GND
OUTPUT A
SHDN
CMPTR
IN–
IN+
SYNC
OSC OUT
CT
RT
DISCHARGE
SOFT START
1
2
3
4
5
6
7
8
TC25C25EOE
TC35C25COE
16
15
14
13
12
11
10
9
VREF
V+
IN
OUTPUT B
VDD
GND
OUTPUT A
SHDN
CMPTR
PIN DESCRIPTION
Pin No.
1
2
3
4
5
6
7
Symbol
IN
–
IN
+
SYNC
OSC OUT
C
T
R
T
DISCHARGE
Description
Error Amplifier inverting input for output voltage reference input and amplifier gain set.
Error Amplifier, non-inverting input for output voltage feedback to regulate voltage.
Input pin for PWM controller oscillator synchronization of two or more controllers from an
external clock output or from another PWM controller oscillator output.
Pin for output of the internal oscillator. This signal can be used as a master oscillator to
sync other oscillators to run at the same timing period.
Pin is the capacitor timing input to set oscillator frequency in conjunction with pin 6 R
T
timing
resistor.
Pin for timing resistor input to set oscillator frequency by setting the charge current into
capacitor C
T
of pin 5.
Pin for discharging the timing capacitor, C
T
of pin 5. During discharging time period, PWM
controller output is disabled. This is called dead time. With a resistor between pin 7 and pin 5,
the dead time can be controlled.
Pin for soft starting the power supply. A capacitor from this pin to GND pin 12 will limit
duty cycle till capacitor is charged above error amplifier output.
Pin for compensation of the feedback loop response.
Pin for terminating both outputs of pins 11 and 14. This will shutdown the power supply
outputs. A positive input with shutdown threshold of 2.4V is required for shutdown.
Pin for output drive of phase A to drive push pull transistor A.
Pin for ground return for all inputs and output signals.
Pin for power supply input to operate the output drivers A and B.
Pin for output drive of phase B to drive push pull transistor B.
Pin for voltage bias supply input for all PWM controller functions except output drive circuits.
Pin is the reference supply output voltage of 4.0 volts that may be used for any voltage
reference purposes such as a reference to control output voltage.
8
9
10
11
12
13
14
15
16
SOFT START
CMPTR
SHDN
OUTPUT A
GND
V
DD
OUTPUT B
V
+
IN
V
REF
4-114
TELCOM SEMICONDUCTOR, INC.
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
