Typical operating characteristics (continued) – Rainbow Electronics MAX1541 User Manual
Page 12
MAX1540/MAX1541
Dual Step-Down Controllers with Saturation
Protection, Dynamic Output, and Linear Regulator
12
______________________________________________________________________________________
Typical Operating Characteristics (continued)
(MAX1541 Circuit of Figure 12, V
IN
= 12V, V
DD
= V
CC
= 5V, SKIP = GND, TON = REF, T
A
= +25°C, unless otherwise noted.)
LINEAR-REGULATOR OUTPUT (LDOOUT)
vs. LOAD CURRENT
MAX1540 toc13
LDO LOAD CURRENT (mA)
LDO OUTPUT VOLTAGE (V)
80
60
20
40
3.22
3.24
3.26
3.28
3.30
3.32
3.34
3.36
3.20
0
100
V
LDOIN
= 5V
V
LDOIN
= 12V
STARTUP WAVEFORM
(HEAVY LOAD)
MAX1540 toc14
3.3V
0
2.5V
0
B
D
C
A
400
µs/div
4A
2A
0
0
A. ON2, 5V/div
B. INDUCTOR CURRENT,
2A/div
0.5
Ω LOAD
C. OUT2, 2V/div
D. PGOOD2, 5V/div
STARTUP WAVEFORM
(LIGHT LOAD)
MAX1540 toc15
3.3V
0
2.5V
0
B
D
C
A
200
µs/div
4A
2A
0
0
A. ON2, 5V/div
B. INDUCTOR CURRENT,
2A/div
100
Ω LOAD
C. OUT2, 2V/div
D. PGOOD2, 5V/div
SHUTDOWN WAVEFORM
(DISCHARGE MODE DISABLED)
MAX1540 toc16
3.3V
0
5V
0
B
D
C
A
10ms/div
2.5V
0
0
0
A. ON2, 5V/div
B. OUT2, 2V/div
C. INDUCTOR CURRENT,
2A/div
100
Ω LOAD, OVP/UVP = REF OR GND
D. DL2, 5V/div
E. PGOOD2, 5V/div
5V
E