Digital Camera Step-Up
Power Supply
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VINPUT = 2.4V, TA = +25°C, unless otherwise noted.)
AUXILIARY CONTROLLER STARTUP
RESPONSE
3.3V
MAX1800 toc13
0V
VON_
5V/div
VOUT
2V/div
0V
IIN
0.5A/div
0A
VOUT = 5V
LOAD = 10Ω
1ms/div
MAIN OUTPUT LOAD-TRANSIENT
RESPONSE
MAX1800 toc15
STARTUP SEQUENCE
MAX1800 toc14
VONM
0V
5V/div
MAIN
OUTPUT
VOLTAGE
2V/div
0V
LDO
OUTPUT
0V
VOLTAGE
2V/div
AUXILIARY
OUTPUT
VOLTAGE
0V
2V/div
1.00ms/div
MAIN LOAD = 24Ω
LDO LOAD = 8Ω
AUXILIARY LOAD = 10Ω
AUXILIARY OUTPUT VOLTAGE = 5V
LDO OUTPUT LOAD TRANSIENT
RESPONSE
MAX1800 toc16
VPOUT
AC COUPLED
100mV/div
LDO
OUTPUT
VOLTAGE
20mV/div
AC COUPLED
IOUT
200mA/div
0A
COUT = 100µF
VOUT = 5V
LOAD = 10Ω
400 us/div
AUXILIARY CONTROLLER OUTPUT
LOAD-TRANSIENT RESPONSE
MAX1800 toc17
VPOUT
AC COUPLED
100mV/div
LDO
LOAD
CURRENT
100mA/div
0A
100µs/div
MAIN OUTPUT RESPONSE DUE
TO LDO TRANSIENT
MAX1800 toc18
MAIN
OUTPUT
VOLTAGE
20mV/div
AC COUPLED
VOUT = 5V
400 us/div
IOUT
200mA/div
0A
200 µs/div
MAIN LOAD = 24Ω
LDO
LOAD
CURRENT
100mA/div
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