Typical operating characteristics (continued) – Rainbow Electronics MAX1821 User Manual
Page 7
MAX1820/MAX1821
WCDMA Cellular Phone 600mA
Buck Regulators
_______________________________________________________________________________________
7
MAX1820/21 toc13
B
C
A
2
µs/div
A: V
LX
, 5V/div
B: INDUCTOR CURRENT, 500mA/div
C: V
OUT
(AC-COUPLED), 20mV/div
LIGHT-LOAD SKIP-SWITCHING WAVEFORMS
(V
IN
= 4.2V, V
OUT
= 1.5V,
LOAD = 30mA, SKIP = GND)
MAX1820/21 toc14
2ms/div
EXITING AND ENTERING SHUTDOWN
(V
IN
= 3.6V, V
OUT
= 3.4V, R
LOAD
= 15
Ω)
V
OUT
2V/div
I
BATT
0.5A/div
V
SHDN
5V/div
MAX1820/21 toc15
40
µs/div
LOAD TRANSIENT (I
LOAD
= 20mA TO 420mA,
V
OUT
= 1.5V, V
IN
= 3.6V, SKIP = BATT)
I
OUT
200mA/div
V
OUT
AC-COUPLED
100mV/div
C
OUT
= 10
µF
MAX1820/21 toc16
40
µs/div
LOAD TRANSIENT (I
LOAD
= 20mA TO 420mA,
V
OUT
= 1.5V, V
IN
= 3.6V, SKIP = GND)
I
OUT
200mA/div
V
OUT
AC-COUPLED
100mV/div
C
OUT
= 10
µF
MAX1820/21 toc17
20
µs/div
MAX1820
REF TRANSIENT (V
REF
= 0.23V TO 1.932V,
R
LOAD
= 10
Ω, V
IN
= 3.6V, SKIP = BATT)
V
REF
1V/div
V
OUT
1V/div
MAX1820/21 toc18
40
µs/div
LINE TRANSIENT (V
IN
= 3.6V TO 4.0V,
V
OUT
= 1.5V, I
LOAD
= 300mA)
V
IN
200mV/div
V
OUT
AC-COUPLED
20mV/div
C
OUT
= 10
µF
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)