28V, Low-Power, High-Voltage,
Boost or Inverting DC-DC Converter
MAX629
____________________________Typical Operating Characteristics (continued)
(SHDN = V
CC
, C
REF
= 0.1µF, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX629-07
REFERENCE VOLTAGE
vs. REFERENCE LOAD CURRENT
V
IN
= V
CC
= 5V
C4 = 0.47µF
REFERENCE VOLTAGE (V)
1.250
MAX629-08
700
V
IN
= V
CC
600
SUPPLY CURRENT (µA)
500
400
I
IN
300
200
100
0
0
1
2
3
4
5
INPUT VOLTAGE (V)
I
CC
I
IN
1.255
1.245
1.240
1.235
1.230
0
20
40
60
80
100 120 140 160
REFERENCE LOAD CURRENT (µA)
OUTPUT VOLTAGE RIPPLE
MAX629-09
LOAD-TRANSIENT RESPONSE
(I
SET
= V
CC
, I
LIM
= 500mA)
MAX629-10
LOAD-TRANSIENT RESPONSE
(I
SET
= GND, I
LIM
= 250mA)
0mA
A
5mA
MAX629-11
0mA
A
5mA
A
B
B
B
10µs/div
V
OUT
= +24V, I
LOAD
= 5mA
A: ISET = V
CC
, 20mV/div
B: ISET = GND, 20mV/div
200µs/div
V
OUT
= +24V, ISET = V
CC
A: LOAD CURRENT, 0mA TO 5mA, 2.5mA/div
B: V
OUT
, AC-COUPLED, 10mV/div
100µs/div
V
OUT
= +24V, ISET = GND
A: LOAD CURRENT, 0mA TO 5mA, 2.5mA/div
B: V
OUT,
AC-COUPLED, 10mV/div
SHUTDOWN TRANSIENT
(POSITIVE CONFIGURATION)
MAX629-12
SHUTDOWN TRANSIENT
(NEGATIVE CONFIGURATION)
5V
SHDN
0V
MAX629-13
5V
SHDN
0V
24V
V
OUT
0V
0V
V
OUT
-20V
50ms/div
V
CC
= V
IN
= 5V, R
L
= 4kΩ
20ms/div
50ms/div
START-UP
= 5V, R
L
=
CC
= V
IN
= 5V, I
LOAD
= 5mA
V
CC
= V
IN
DELAY, V
4kΩ
4
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
