Step-Up Converter
for Handheld Applications
Typical Operating Characteristics
(V = 3.6V, C
IN
= 22µF, X5R, 6.3V local and 10µF, X5R, 6.3V, 1µH inductor, circuit of Figure 1, T = +25NC, unless otherwise noted.)
A
OUT
STARTUP (V
= 3.7V)
MAX8969 toc16
LIGHT-LOAD RIPPLE
OUT
MAX8969 toc15
2V/div
C
, TYP = 32µF,
OUT
AC-COUPLED
20mV/div
0
TREN = GND,
V
V
OUT
EN
I
= 10mA,
= 2.6V
OUT
2V/div
V
IN
0
V
OUT
V
LX
2V/div
0
2V/div
V
LX
I
= 1mA, V = 3.6V
IN
OUT
0
200µs/div
40µs/div
HARD-SHORT (V
= 3.7V)
MAX8969 toc18
STARTUP (V
= 5V)
MAX8969 toc17
OUT
OUT
V
OUT
2V/div
2V/div
C
, TYP = 32µF,
OUT
0
0
TREN = GND,
V
EN
I
V
= 10mA,
= 3.2V
2A/div
OUT
IN
2V/div
I
0
OUT
V
2V/div
LX
0
V
OUT
0
2V/div
V
= 3.2V, 0.1I LOAD
IN
V
LX
2A/div
I
LX
0
0
40µs/div
200µs/div
HARD-SHORT (V
= 5V)
MAX8969 toc19
SHUTDOWN
OUT
MAX8969 toc20
V
EN
2V/div
V
I
2V/div
OUT
0
0
2A/div
0
2V/div
OUT
V
OUT
2V/div
0
V
LX
V
LX
2V/div
0
0
V
= 3.2V, 0.1I LOAD
IN
2A/div
0
10I LOAD, TREN = GND
I
LX
20µs/div
2µs/div
_______________________________________________________________________________________
7
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
