Typical operating characteristics (continued) – Rainbow Electronics MAX1844 User Manual
Page 7
MAX1844
High-Speed Step-Down Controller with
Accurate Current Limit for Notebook Computers
_______________________________________________________________________________________
7
0
2
6
4
8
10
0
10
5
15
20
25
30
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (PWM MODE)
MAX1844 toc10
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
I
IN
I
DD
I
CC
0.8
0.6
0.4
0.2
0
0
15
5
10
20
25
30
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (SKIP MODE)
MAX1844 toc11
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
I
CC
I
IN
I
DD
20
µ
s/div
LOAD-TRANSIENT RESPONSE
(PWM MODE)
INDUCTOR
CURRENT
2A/div
V
OUT
AC COUPLED
100mV/div
DL
5V/div
MAX1844 toc12A
20
µ
s/div
LOAD-TRANSIENT RESPONSE
(SKIP MODE)
INDUCTOR
CURRENT
2A/div
V
OUT
AC COUPLED
100mV/div
DL
5V/div
MAX1844 toc12B
500
µ
s/div
STARTUP WAVEFORM
INDUCTOR
CURRENT
5A/div
V
OUT
1V/div
MAX1844 toc14
SHDN
5V/div
DL
5V/div
40
µ
s/div
OUTPUT OVERLOAD WAVEFORM
(UVP = GND)
V
OUT
1V/div
DL
5V/div
INDUCTOR
CURRENT
5A/div
MAX1844 toc13A
R
LOAD
= 112m
Ω
40
µ
s/div
OUTPUT OVERLOAD WAVEFORM
(UVP = V
CC
, OVP = GND)
V
OUT
1V/div
DL
5V/div
INDUCTOR
CURRENT
5A/div
MAX1844 toc13B
R
LOAD
= 112m
Ω
100
µ
s/div
SHUTDOWN WAVEFORM
(OVP = GND)
V
OUT
1V/div
DL
5V/div
INDUCTOR
CURRENT
5A/div
MAX1844 toc15A
R
LOAD
= 1
Ω
100
µ
s/div
SHUTDOWN WAVEFORM
(OVP = V
CC
)
V
OUT
1V/div
DL
5V/div
INDUCTOR
CURRENT
5A/div
MAX1844 toc15B
R
LOAD
= 1
Ω
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= 15V, SKIP = GND, TON = unconnected, T
A
= +25°C, unless otherwise noted.)