TC170 Datasheet, PDF (1/16 Pages) TelCom Semiconductor, Inc – CMOS CURRENT MODE PWM CONTROLLER

TC170
CMOS Current Mode PWM Controller
Features
• Low Supply Current With CMOS Technology:
3.8mA Max
• Internal Reference: 5.1V
• Fast Rise/Fall Times (C_L = 1000pF): 50nsec
• Dual Push-Pull Outputs
• Direct-Power MOSFET Drive
• High Totem-Pole Output Drive: 300mA
• Differential Current-Sense Amplifier
• Programmable Current Limit
• Soft-Start Operation
• Double-Pulse Suppression
• Undervoltage Lockout
• Wide Supply Voltage Operation: 8V to 16V
• High Frequency Operation: 200kHz
• Available with Low OFF State Outputs
• Low Power, Pin-Compatible Replacement for
UC3846
Applications
• Switching Power Supplies
• DC/DC Converters
• Motor Control
Device Selection Table
Part Number
Package
Temp. Range
TC170COE 16-Pin SOIC (Wide) 0°C to +70°C
TC170CPE 16-Pin PDIP (Narrow) 0°C to +70°C
Package Type
16-Pin PDIP (Narrow)
SOFT START/
I_LIM ¹
V_REFOUT 2
– I _SENSE IN ₃
16 SHDN
15 _IN
+ I _SENSE IN 4
TC170CPE
DD
+ ERROR AMP IN 5
– ERROR AMP IN 6
CMPTR 7
C_{O 8}
9 R_O
General Description
The TC170 offers maximum supply current of 3.8mA.
Bipolar current-mode control integrated circuits require
five times more operating current.
The dual totem-pole CMOS outputs drive power
MOSFETs or bipolar transistors. The 50nsec typical
output rise and fall times (1000pF capacitive loads)
minimize MOSFET power dissipation. Output peak
current is 300mA.
The TC170 contains a full array of system-protection
circuits (see Features Section).
Current-mode control lets users parallel power supply
modules. Two or more TC170 controllers can be slaved
together for parallel operation. Circuits can operate
from a master TC170 internal oscillator or an external
system oscillator.
The TC170 operates from an 8V to 16V power supply.
An internal 2%, 5.1V reference minimizes external
component count. The TC170 is pin compatible with
the Unitrode UC1846/UC2846/UC3846 bipolar
controller.
Other advantages inherent in current-mode control
include superior line and load regulation and automatic
symmetry correction in push-pull converters.
16-Pin SOIC (Wide)
SOFT START/
I_LIM
V_REFOUT
– I _SENSE IN
+ I _SENSE IN
+ ERROR AMP IN
1
16
2
15
3
14
4
13
TC170COE
5
12
SHDN
V_IN
OUTPUT B
V_DD
GND
– ERROR AMP IN 6
CMPTR 7
11 _{OUTPUT A}
10 _SYNC
C_O 8
9 R_O
NOTE: Outputs LOW in "OFF" state.
© 2002 Microchip Technology Inc.
DS21395B-page 1