TC170 Datasheet, PDF (2/16 Pages) TelCom Semiconductor, Inc – CMOS CURRENT MODE PWM CONTROLLER

TC170
Functional Block Diagram
V_REF
2
V_IN ¹⁵
5.1-Volt
Reference
R_O ⁹
C_O ⁸
Oscillator
Undervoltage
Lockout
10
Sync
(–) Current 3
Sense Input
(+) Current ⁴
Sense Input
7
Comp
(+) Error 5
Amp Input
(–) Error 6
Amp Input
x 3.15 Current
–
Amplifier
–
+
+
0.75V
PWM
Comparator
+
–
V_DD
100µA
+
Limit Buffer
Amplifier
–
Q4
R
Q
S
S
PWM Latch
Error
Amplifier
350mV
Lock-up
Amplifier
–
+
Positive
Feedback
Q1 Q2
Q3
3.5kΩ
DQ
C
Q
TC170
13 _VDD
Output
11 _{A (}
)
14 Output
B( )
12
Ground
1 _{Current Limit/}
Soft-Start Adjust
Shutdown
Comparator
350
mV
6kΩ
16
Shutdown
NOTE: Outputs low in OFF state.
DS21395B-page 2
© 2002 Microchip Technology Inc.