Typical operating characteristics (continued) – Rainbow Electronics MAX1688 User Manual
Page 5
MAX1687/MAX1688
Step-Up DC-DC Converters with
Precise, Adaptive Current Limit for GSM
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(
V
IN
= +3.3V, V
OUT
= 5V, V
LIM
= 1V, Figures 6b and 7, T
A
= +25°C, unless otherwise noted.
)
500mA/div
500mA/div
200mV/div
V
OUT
1ms/div
I
LX
I
LOAD
MAX1688
SWITCHING WAVEFORMS
(GSM PULSED LOAD 1A, R
CHG
= 40.2k
Ω
)
MAX1687/88 toc11
R
CHL
= 40.2k
Ω
, L = 10
µ
H
200mA/div
0A
V
LIM
= 1V
V
LIM
= 0
2
µ
s/div
I
LX
I
LX
INDUCTOR CURRENT
MAX1687/88 toc13
200mA/div
1V/div
I
BATTERY
V
ON
10
µ
s/div
MAX1687/88 toc15
V
ON
vs. BATTERY CURRENT
2V/div
1V/div
V
ON
V
OUT
5ms/div
MAX1687/88 toc14
POWER-UP WAVEFORM
(R
LOAD
= 15
Ω
C
OUT
= 2000
µ
F)
500mA/div
500mA/div
200mV/div
V
OUT
1ms/div
I
LX
I
LOAD
MAX1688
SWITCHING WAVEFORMS
(GSM PULSED LOAD 1A, R
CHG
= 18k
Ω
)
MAX1687/88 toc12
R
CHG
= 18k
Ω
, L = 10
µ
H
500mA/div
100mV/div
V
OUT
500
µ
s/div
I
LX
SWITCHING WAVEFORMS
(FIXED I
LOAD
= 300mA)
MAX1687/88 toc10a