TC170 Datasheet, PDF (5/16 Pages) TelCom Semiconductor, Inc – CMOS CURRENT MODE PWM CONTROLLER

TC170
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1: PIN FUNCTION TABLE
Pin No.
(16-Pin PDIP,
SOIC)
Symbol
Description
1
SOFT START/I_LIM Soft Start Adjust/Current Limit. For setting the peak current threshold of sense inputs (pins 3
and 4). Second function of this pin is Soft-Start Adjust.
2
V_REFOUT
Reference supply output of 5.1 volts. It can supply a minimum of 10mA.
3
-I_SENSEIN
-Current Sense Input. Inverting input for sensing peak current of the pass transistor through
series sense current monitor resistor.
4
+I_SENSEIN
+Current Sense Input. Non-inverting input used in conjunction with pin 3. This senses the
positive end of current monitor resistor.
5
+ERROR AMP IN +Error Amp In. Non-inverting input for output voltage regulation.
6
-ERROR AMP IN -Error Amp In. Inverting input of the amplifier for the reference voltage.
7
CMPTR
For compensation of the feedback loop response.
8
C_O
Timing capacitor (C_O) input to set oscillator frequency in conjunction with pin 9, R_O, resistor
input. Second function is for setting crossover dead time of pin 11and 14 outputs.
9
R_O
Timing resistor (R_O) input to set oscillator frequency by setting constant current charge rate to
charge capacitor C_O.
10
SYNC
For PWM controller oscillator synchronization of two or more controllers. Or as a clock input to
sync oscillator from external signal.
11
OUTPUT A A output drive of phase A from push pull transistors.
12
GND
Ground return for all input and output pins.
13
V_DD
Supplies power to operate the output drivers only.
14
OUTPUT B Output of phase B from push pull transistors.
15
V_IN
Voltage bias supply for all TC170 circuits except the output transistors.
16
SHDN
Input pin to disable both output drives to 0V OFF.
© 2002 Microchip Technology Inc.
DS21395B-page 5