MB39A123 Datasheet, PDF (15/44 Pages) Fujitsu Component Limited. – 6 ch DC/DC Converter IC with Synchronous Rectification

MB39A123
ON Duty Cycle vs. DTC Terminal Voltage
100
95
Ta = + 25 °C
VCC = CTL = 4 V
FB = 2 V
90 _{CT = 100 pF}
85
fosc = 200 kHz
fosc = 1 MHz
80
75
fosc = 2 MHz
70
65
60
55
50
0.6
0.65
0.7
0.75
0.8
0.85
0.9
DTC Terminal Voltage VDTC (V)
Maximum Duty Cycle vs. Power Supply Voltage
100
fosc = 200 kHz
95
fosc = 1 MHz
90
Ta = + 25 °C
VCC = CTL
85
DTC pin open
fosc = 2 MHz
FB = 2 V
CT = 100 pF
80
75
70
0
2
4
6
8
10
12
Power Supply Voltage VCC (V)
Start Power Supply Voltage vs. Timing Resistor
2
At evaluating Fujitsu EV board system
1.9
1.8 Ta = −30 °C
1.7
Ta = + 25 °C
1.6
1.5
1.4
1.3
1.2
1.1
VCTL = VCC
CT = 100 pF
1
1
10
100
Timing Resistor RT (kΩ)
Maximum Duty Cycle vs. Oscillation Frequency
100
Ta = + 25 °C
VCC = 4 V
95
CTL = 4 V
FB = 2 V
DTC = Open
90
RT = 3 kΩ
RT = 39 kΩ
85
RT = 13 kΩ
RT = 6.8 kΩ
80
75
70
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200
Oscillation Frequency fOSC (kHz)
Maximum Duty Cycle vs.
Operating Ambient Temperature
100
fosc = 200 kHz
95
90
fosc = 1 MHz
85
fosc = 2 MHz
80
Ta = + 25 °C
VCC = CTL = 4 V
75
DTC pin open
FB = 2 V
CT = 100 pF
70
−40 −20
0
+20 +40 +60 +80 +100
Operating Ambient Temperature Ta ( °C)
(Continued)
15