WCDMA Cellular Phone 600mA
Buck Regulators
(TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
LIGHT-LOAD SKIP-SWITCHING WAVEFORMS
(VIN = 4.2V, VOUT = 1.5V,
LOAD = 30mA, SKIP = GND)
MAX1820/21 toc13
EXITING AND ENTERING SHUTDOWN
(VIN = 3.6V, VOUT = 3.4V, RLOAD = 15Ω)
MAX1820/21 toc14
A
VSHDN
5V/div
B
C
2µs/div
A: VLX, 5V/div
B: INDUCTOR CURRENT, 500mA/div
C: VOUT (AC-COUPLED), 20mV/div
LOAD TRANSIENT (ILOAD = 20mA TO 420mA,
VOUT = 1.5V, VIN = 3.6V, SKIP = BATT)
MAX1820/21 toc15
VOUT
2V/div
IBATT
0.5A/div
2ms/div
LOAD TRANSIENT (ILOAD = 20mA TO 420mA,
VOUT = 1.5V, VIN = 3.6V, SKIP = GND)
MAX1820/21 toc16
IOUT
200mA/div
IOUT
200mA/div
VOUT
AC-COUPLED
100mV/div
40µs/div
COUT = 10µF
MAX1820
REF TRANSIENT (VREF = 0.23V TO 1.932V,
RLOAD = 10Ω, VIN = 3.6V, SKIP = BATT)
MAX1820/21 toc17
VREF
1V/div
VOUT
AC-COUPLED
100mV/div
40µs/div
COUT = 10µF
LINE TRANSIENT (VIN = 3.6V TO 4.0V,
VOUT = 1.5V, ILOAD = 300mA)
MAX1820/21 toc18
VIN
200mV/div
VOUT
1V/div
VOUT
AC-COUPLED
20mV/div
COUT = 10µF
20µs/div
40µs/div
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