Rainbow Electronics MAX744A - Manual (Page 6)

MAX730A/MAX738A/MAX744A
5V, Step-Down,
Current-Mode PWM DC-DC Converters
6 _______________________________________________________________________________________
MAX738A/MAX744A
SWITCHING WAVEFORMS,
CONTINUOUS CONDITION
2 µ s/div
A: SWITCH VOLTAGE (LX PIN), 5V/div, 0V TO +12V
B: INDUCTOR CURRENT, 200mA/div
C: OUTPUT VOLTAGE RIPPLE, 50mV/div, AC-COUPLED
COUT = 390 µ F,
V+ = 12V, IOUT = 150 µ A,
MAX738A/MAX744A
SWITCHING WAVEFORMS,
DISCONTINUOUS CONDITION
2 µ s/div
A: SWITCH VOLTAGE (LX PIN), 5V/div, 0V TO +12V
B: INDUCTOR CURRENT, 200mA/div
C: OUTPUT VOLTAGE RIPPLE, 50mV/div, AC-COUPLED
COUT = 390 µ F,
V+ = 12V, IOUT = 150 µ A
12V
0V
200mA
0mA
A
B
C
0V
200mA
0mA
A
B
C
MAX730A LINE-TRANSIENT RESPONSE
100ms/div
A: VOUT, 50mV/div, DC-COUPLED
B: V+, 5V/div, 6.0V TO 11.0V
IOUT = 300mA
MAX738A/MAX744A LINE-TRANSIENT RESPONSE
100ms/div
A: VOUT, 50mV/div, DC-COUPLED
B: V+, 5V/div, 10.2V TO 16.0V
IOUT = 750mA
11V
6V
0V
A
B
16V
10.2V
A
B
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 3, T
A
= +25°C, unless otherwise noted.)
12V
0V