Typical operating characteristics – Rainbow Electronics MAX8775 User Manual
Page 7
MAX8775
Dual and Combinable Graphics Core
Controller for Notebook Computers
_______________________________________________________________________________________
7
1-PHASE EFFICIENCY
vs. LOAD CURRENT (V
OUT
= 1.5V)
MAX8775 toc01
LOAD CURRENT (A)
EFFICIENCY (%)
10
1
50
60
70
80
90
100
40
0.1
100
V
IN
= 7V, PWM
V
IN
= 12V, PWM
V
IN
= 20V, PWM
V
IN
= 7V, SKIP
V
IN
= 12V, SKIP
V
IN
= 20V, SKIP
2-PHASE EFFICIENCY
vs. LOAD CURRENT (V
OUT
= 1.5V)
MAX8775 toc02
LOAD CURRENT (A)
EFFICIENCY (%)
10
1
50
60
70
80
90
100
40
0.1
100
V
IN
= 7V, PWM
V
IN
= 12V, PWM
V
IN
= 20V, PWM
V
IN
= 7V, SKIP
V
IN
= 12V, SKIP
V
IN
= 20V, SKIP
EFFICIENCY
vs. LOAD CURRENT (V
OUT
= 1.5V)
MAX8775 toc03
LOAD CURRENT (A)
EFFICIENCY (%)
10
1
50
60
70
80
90
100
40
0.1
100
1-PHASE, PWM
V
IN
= 12V
V
OUT
= 1.5V
2-PHASE, PWM
1-PHASE, SKIP
2-PHASE, SKIP
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX8775 toc04
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
20
25
10
15
5
1.497
1.499
1.501
1.503
1.505
1.495
0
30
PWM MODE
SKIP MODE
V
IN
= 12V
V
OUT
= 1.5V
EFFICIENCY
vs. LOAD CURRENT (V
OUT
= 1.2V)
MAX8775 toc05
LOAD CURRENT (A)
EFFICIENCY (%)
10
1
50
60
70
80
90
100
40
0.1
100
1-PHASE, PWM
V
IN
= 12V
V
OUT
= 1.2V
2-PHASE, PWM
1-PHASE, SKIP
2-PHASE, SKIP
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (SKIP MODE)
MAX8775 toc06
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
16
20
8
12
4
0.01
0.1
1
10
0.001
0
24
I
CC
I
DD
I
IN
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (1-PHASE PWM MODE)
MAX8775 toc07
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
16
20
8
12
4
10
100
1
0
24
I
CC
I
DD
I
IN
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE (2-PHASE PWM MODE)
MAX8775 toc08
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
16
20
8
12
4
10
100
1
0
24
I
CC
I
DD
I
IN
CURRENT-SENSE OFFSET
vs. LOAD CURRENT (2-PHASE PWM MODE)
MAX8775 toc09
LOAD CURRENT (A)
CURRENT BALANCE OFFSET (mV)
20
25
10
15
5
0
-0.5
0.5
1.0
-1.0
0
30
Typical Operating Characteristics
(Circuit of Figure 1, V
IN =
12V, V
DD
= V
CC
= 5V,
SKIP_ = GND, T
A =
+25°C, unless otherwise noted.)