Typical operating characteristics – Rainbow Electronics MAX747 User Manual
Page 3
MAX747
High-Efficiency PWM, Step-Down
P-Channel DC-DC Controller
_______________________________________________________________________________________
3
0
-75
SUPPLY CURRENT vs.
TEMPERATURE
1
MAX747-TOC1
TEMPERATURE (°C)
3
2
4
-50 -25
0
25
50
75
100 125
V
IN
= 9V
V
OUT
= 5V
SCHOTTKY DIODE
LEAKAGE EXCLUDED
ENTIRE
CIRCUIT
SUPPLY CURRENT (mA)
0.6
5
SUPPLY CURRENT vs.
SUPPLY VOLTAGE
0.7
MAX747-TOC2
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
13
0.9
0.8
7
11
15
1.0
9
2
0.4
CONTINUOUS-CONDUCTION MODE BOUNDARY
AND CORRESPONDING PEAK INDUCTOR CURRENT (V
OUT
= 3.3V)
6
MAX747-TOC3
OUTPUT CURRENT (A)
SUPPLY VOLTAGE (V)
1.2
14
10
0.6
1.0
1.4
18
0.8
CONTINUOUS
CONDUCTION
REGION
V
OUT
= 3.3V
L = 33µH
R
SENSE
= 50m
Ω
DISCONTINUOUS
CONDUCTION
REGION
PEAK
INDUCTOR
CURRENT
0.4
0.8
1.6
1.2
2.0
PEAK INDUCTOR CURRENT (A)
5
0.5
CONTINUOUS-CONDUCTION MODE BOUNDARY
AND CORRESPONDING PEAK INDUCTOR CURRENT (V
OUT
= 5V)
9
MAX747-TOC4
OUTPUT CURRENT (A)
SUPPLY VOLTAGE (V)
13
11
0.7
1.3
15
1.1
0.9
CONTINUOUS
CONDUCTION
REGION
PEAK INDUCTOR
CURRENT
V
OUT
= 5V
L = 50µH
R
SENSE
= 50m
Ω
DISCONTINUOUS
CONDUCTION
REGION
PEAK INDUCTOR CURRENT (A)
7
0.4
0.8
1.6
1.2
2.0
100
70
0.01
0.1
10
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 5V)
80
90
MAX1747-TOC7
OUTPUT CURRENT (A)
EFFICIENCY (%)
1
V
IN
= 12V
V
IN
= 9V
V
IN
= 6V
3
0
0.01
0.1
10
PEAK INDUCTOR CURRENT vs.
OUTPUT CURRENT (V
OUT
= 5V)
1
2
MAX747-TOC5
OUTPUT CURRENT (A)
PEAK INDUCTOR CURRENT (A)
1
V
IN
= 12V
V
IN
= 9V
V
IN
= 6V
3
0
0.01
0.1
10
PEAK INDUCTOR CURRENT vs.
OUTPUT CURRENT (V
OUT
= 3.3V)
1
2
MAX747-TOC6
OUTPUT CURRENT (A)
PEAK INDUCTOR CURRENT (A)
1
V
IN
= 9V
V
IN
= 6V
V
IN
= 5V
100
70
0.01
0.1
10
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 3.3V)
80
90
MAX747-TOC8
OUTPUT CURRENT (A)
EFFICIENCY (%)
1
VIN = 6V
VIN = 9V
VIN = 12V
__________________________________________Typical Operating Characteristics
(Circuit of Figure 1, V+ = 9V, T
A
= +25°C, unless otherwise noted.)