Typical operating characteristics (continued) – Rainbow Electronics MAX8715 User Manual
Page 7
MAX1790/MAX8715
Low-Noise Step-Up DC-DC Converters
_______________________________________________________________________________________
7
2ms/div
STARTUP WAVEFORM
WITH SOFT-START
MAX1790 toc13
CH1
CH2
CH3
CH1 = SHDN, 5V/div
CH2 = V
OUT,
5V/div
CH3 = INDUCTOR CURRENT, 500mA/div
V
OUT
= 12V, I
OUT
= 200mA, f
OSC
= 640kHz,
C
SS
= 0.027
µF
CH1
CH2
CH3
CH1 = LX SWITCHING WAVEFORM, 5V/div
CH2 = OUTPUT VOLTAGE, AC-COUPLED, 200mV/div
CH3 = INDUCTOR CURRENT, 1A/div
V
OUT
= 12V, I
OUT
= 200mA, f
OSC
= 640kHz, L = 10
µH;
C
OUT
= 33
µF + 0.1µF
500ns/div
SWITCHING WAVEFORM
MAX1790 toc14
0
400
200
800
600
1000
1200
1600
1400
1800
3.0
3.4 3.6 3.8
3.2
4.0 4.2 4.4
4.8
4.6
5.0
MAX1790 MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1790 toc15
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
f
OSC
= 640kHz
V
OUT
= 12V
V
OUT
= 5V
0
400
200
800
600
1000
1200
1600
1400
1800
3.0
3.4 3.6 3.8
3.2
4.0 4.2 4.4
4.8
4.6
5.0
MAX8715 MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX1790 toc16
INPUT VOLTAGE (V)
MAXIMUM OUTPUT CURRENT (mA)
V
OUT
= 9V
f
OSC
= 1.2MHz
L = 6.8
µH
C
OUT
= 3 x 3.3
µF
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= 3.3V, f
OSC
= 640kHz, T
A
= +25°C, unless otherwise noted.)