Datasheet

MAX8792
Single Quick-PWM Step-Down
Controller with Dynamic REFIN
8 _______________________________________________________________________________________
NO-LOAD SUPPLY CURRENT I
IN
vs. INPUT VOLTAGE
MAX8792 toc13
INPUT VOLTAGE (V)
I
IN
(mA)
12 15 18 219
0.1
1
10
100
0.01
624
SKIP MODE
PWM MODE
LOW-NOISE MODE
REF OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX8792 toc14
LOAD CURRENT (μA)
OUTPUT VOLTAGE (V)
30 50 70 90 10010 20 40 60 800
1.99
2.00
2.01
2.02
1.98
-10 110
REFIN-TO-FB OFFSET
VOLTAGE DISTRIBUTION
MAX8792 toc15
OFFSET VOLTAGE (mV)
SAMPLE PERCENTAGE (%)
10
30
20
40
50
+85°C
+25°C
SAMPLE SIZE = 100
0
-2.5 -2.0 -1.5 -1.0 -0.5
0
0.5 1.0 1.5 2.0 2.5
20V ILIM THRESHOLD
VOLTAGE DISTRIBUTION
MAX8792 toc16
ILIM THRESHOLD VOLTAGE (mV)
SAMPLE PERCENTAGE (%)
20
10
40
30
50
0
18.0 18.4 18.8 19.2 19.6 20.0 20.4 20.8 21.2 21.6 22.0
+85°C
+25°C
SAMPLE SIZE = 100
SOFT-START WAVEFORM
(HEAVY LOAD)
MAX8792 toc17
200μs/div
C. V
OUT
, 1V/div
B. INDUCTOR CURRENT,
10A/div
1.5V
8A
0
5V
0
0
0
5V A
B
C
D
A. EN, 5V/div
B. PGOOD, 5V/div
SOFT-START WAVEFORM
(LIGHT LOAD)
MAX8792 toc18
200μs/div
C. V
OUT
, 1V/div
B. INDUCTOR CURRENT,
10A/div
1.5V
0
5V
0
0
0
5V A
B
C
D
A. EN, 5V/div
B. PGOOD, 5V/div
SHUTDOWN WAVEFORM
MAX8792 toc19
200μs/div
D. V
OUT
, 1V/div
E. INDUCTOR CURRENT,
5A/div
1.5V
0
5V
5V
0
0
0
0
5V
A
B
C
D
E
A. EN, 5V/div
B. PGOOD, 5V/div
C. DL, 5V/div
LOAD-TRANSIENT RESPONSE
(PWM MODE)
MAX8792 toc20
20μs/div
C. INDUCTOR CURRENT,
10A/div
1.45V
8A
1A
1.55V
8A
1A
A
B
C
A. I
OUT
= 1A TO 8A, 10A/div
B. V
OUT
, 50mV/div
LOAD-TRANSIENT RESPONSE
(SKIP MODE)
MAX8792 toc21
20μs/div
C. INDUCTOR CURRENT,
10A/div
1.45V
8A
1A
1.55V
10A
0A
A
B
C
A. I
OUT
= 1A TO 8A, 10A/div
B. V
OUT
, 50mV/div
Typical Operating Characteristics (continued)
(MAX8792 Circuit of Figure 1, V
IN
= 12V, V
DD
= 5V, SKIP = GND, R
TON
= 200kΩ, T
A
= +25°C, unless otherwise noted.)