Typical operating characteristics (continued) – Rainbow Electronics MAX8758 User Manual
Page 8
MAX8758
Step-Up Regulator with Switch Control and
Operational Amplifier for TFT LCD
8
_______________________________________________________________________________________
Typical Operating Characteristics (continued)
(Circuit of
Figure
1, V
IN
= 3.3V, V
MAIN
= 8.5V, FREQ =
SHDN = IN, T
A
= +25°C, unless otherwise noted.)
OP-AMP LARGE-SIGNAL STEP RESPONSE
MAX8758 toc17
1µs/div
V
OUTB
2V/div
OP-AMP SMALL-SIGNAL STEP RESPONSE
MAX8758 toc18
200ns/div
V
POSB
100mV/div
AC-COUPLED
V
OUTB
200mV/div
AC-COUPLED
HIGH-VOLTAGE SWITCH CONTROL FUNCTION
(MODE 1)
MAX8758 toc19
400µs/div
V
MODE
V
CTL
V
GON
HIGH-VOLTAGE SWITCH CONTROL FUNCTION
(MODE 2)
MAX8758 toc20
400µs/div
V
MODE
V
CTL
V
GON
POSITIVE CHARGE-PUMP OUTPUT VOLTAGE
vs. CHARGE-PUMP LOAD CURRENT
MAX8758 toc21
CHARGE-PUMP LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
15
10
5
21
22
23
24
25
20
0
20
V
IN
= 3.3V
f
OSC
= 1.2MHz
-9
-8
-7
-6
-5
-10
NEGATIVE CHARGE-PUMP OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX8758 toc22
CHARGE-PUMP LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
15
10
5
0
20
V
IN
= 3.3V
f
OSC
= 1.2MHz