FAN5070 Datasheet, PDF (6/14 Pages) Fairchild Semiconductor – High Performance Programmable Synchronous DC-DC Controller

Typical Operating Characteristics (continued)
Output Startup, System Power-up
FAN5070
Output Startup from Enable
Time (10ms/division)
Application Circuit
L1
(Optional)
+5V
C_IN*
Time (20ms/div)
R1
R2
C2
VO
C_OUT*
VID4
VID3
VID2
VID1
VID0
3.3V
R3
Q1
L2
D1 ^Q2
R4
R8–12
VCC
R5
PWRGD
C4
R6
C1
1
20
2
19
3
18
4
17
5
U1
16
6 ^FAN5070 15
7
14
8
13
9
12
10
11
Figure 1. Application Circuit for VRM8.5 Motherboards
(Worst Case Analyzed! See Appendix for Details)
R7
+12V
C6
C5
ENABLE/SS
C3
REV. 1.0.1 8/7/01
6