M62501P/FP
M62501 Application
IN−
R2
C5
VR1
C2
D1
16
V
CC
15
14
13
C3
R1
C4
R4
12
+
VREF
11
10
+
−
−
Comp
−
+
Latch
V
REF
UVLO
GEN
V
CC
1
2
3
C
OSC
4
C
AGC
5
6
7
8
AGC
+
+
9
R3
IN+
BO
BI
PWM OUT
C1
T
IN
P. OUT
OVP
UVP
C1, C2: Stabilization capacitors of V
CC
and V
REF
.
VR1: It is decided considering a load capacity of V
REF
.
(A load capacity is approximately 5 mA.)
Recommended value is around 10 kΩ.
C3, Dl: They are for the soft start function. A time constant is decided considering VR1.
C
AGC
: This capacitor is for stabilization of AGC. A larger capacitor improves a stability of the system, however
a system response is degraded.
Recommended value is around 1
µF.
C
OSC
: This capacitor is for a saw wave generation. Recommended value is around 1000 pF.
R1, R2, R3, R4, C4, C5:
They are for a gain setting of the error Amp. R2 should be several kΩ to dozens of kΩ to set a voltage gain
20 dB to 40 dB at f = 1 kHz, so that the feed back loop is stable.
When the voltage gain is too low, it causes jitter.
Recommended values of C4, C5 and R1 are ;
C4 = dozens of pF to several hundreds pF
C5 = several thousands pF to tens of thousands pF
R1 = dozens of kΩ to several hundreds kΩ.
Note: Connect 7-pin and 8-pin terminal to GND when don't use under voltage protection. (UVP)
Rev.2.00 Jun 14, 2006 page 8 of 10
RENESAS [ RENESAS TECHNOLOGY CORP ]
