mic9131 Micrel Semiconductor, mic9131 Datasheet - Page 8

• Manufacturer Part Number: mic9131
• Description: Mic9131 High-voltage, High-speed Telecom Dc-to-dc Controller
• Manufacturer: Micrel Semiconductor

MIC9131
Functional Block Diagram
M9999-080206
VBIAS
RBIAS
CPWR
ISNS
LINE
VCC
EN
SS
14
9
10
3
12
8
2
1
5V
5V
FB
7
4µA
BIAS
REG
1.21V
Amplifier
40µA
COMP
Error
0.82V
Shutdown
Thermal
6
OSC
1.2V
Q
Oscillator
PWM
Current Limit
Duty Cycle
Note:
Output switching frequency is 1/4 the oscillator frequency.
4
Max.
1000000
5
Peak
SYNC
R1
R2
100000
S
10000
1000
10000
Oscillator Frequency vs.
13
UVLO
220 p F
470 p F
680 p F
1000 p F
2200 p F
100 p F
47pF
2
2
100000
FREQUENCY (Hz)
VCC
UVLO
LINE
UVLO
Figure 1
RC Values
Current
Limit
Selection
8
MAXIMUM DUT Y CYCLE
1000000 10000000
1-Shot
UNDERVOLTAGE LOCKOU T
R
S1
S2
SR Latch
Q
*See applications section for higher
switching frequencies
VCC
16
15
11
OUT
PGND
AGND
August 2006
Micrel, Inc.