Typical operating characteristics (continued) – Rainbow Electronics MAX1688 User Manual
Page 4
MAX1687/MAX1688
Step-Up DC-DC Converters with Precise,
Adaptive Current Limit for GSM
4
_______________________________________________________________________________________
_____________________________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.
)
300
450
400
350
500
550
600
650
700
750
800
100
200
150
250
300
350
400
MAX1688
I
PEAK
vs. V
OUT
DROOP
MAX1687/88 toc09
V
OUT
DROOP (mV)
I
PEAK
(mA)
R
CHG
= 40.2k
0
800
700
600
500
400
300
200
100
15
20
25
30
35
40
MAX1688 PEAK INDUCTOR CURRENT
vs. R
CHG
(1A GSM LOAD)
MAX1687/88 toc10
R
CHG
(k
Ω
)
PEAK INDUCTOR CURRENT (mA)
0
100
200
300
400
500
600
700
800
15
20
25
30
35
40
MAX1688 PEAK BATTERY CURRENT
vs. R
CHG
(1A GSM LOAD)
MAX1687/88 toc04
R
CHG
(k
Ω
)
PEAK BATTERY CURRENT (mA)
1.5
2.5
2.0
3.5
3.0
4.0
4.5
-40
20
40
-20
0
60
80
100
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
NO-LOAD BATTERY INPUT CURRENT vs.
TEMPERATURE (V
OUT
= 5V, V
LIM
= 1V )
MAX1687/88 toc05
V
IN
= 5V
V
IN
= 3.3V
V
IN
= 2.7V
V
IN
= 6V
REFERENCE VOLTAGE vs. REFERENCE
CURRENT (V
IN
= 3.3V, V
OUT
= 5V)
MAX1687/88 toc06
I
REF
(
µ
A)
V
REF
(V)
1.245
1.200
1
1000
100
10
1.215
1.205
1.235
1.225
1.250
1.220
1.210
1.240
1.230
1.245
1.247
1.249
1.251
1.253
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
-40
20
40
-20
0
60
80
100
REFERENCE VOLTAGE vs. TEMPERATURE
(V
IN
= 3.3V, V
OUT
= 5V)
MAX1687/88 toc07
1200
0
1
10
100
SWITCHING FREQUENCY vs. INDUCTANCE
(V
IN
= 3.3V, V
OUT
= 5V,
I
LOAD
= 100mA, V
LIM
= 1V)
200
MAX1687/88 toc08
INDUCTANCE (
µ
H)
FREQUENCY (kHz)
600
400
1000
800