UNR-2.5/10-D12 查看數據表（PDF） - DATEL Data Acquisition products
零件编号
产品描述 (功能)
生产厂家
UNR-2.5/10-D12 Datasheet PDF : 7 Pages
| |||
UNR Series
N O N - I S O L AT E D, 3 . 3 V, 8 - 4 0 W D C / D C C O N V E R T E R S
Technical Notes
Input Capacitors
As shown in the simplified schematic, UNR Series power converters do not
have internal input capacitors. Users must install external input capacitors
for the devices to achieve specified operation. The input capacitor functions
as a true energy-storage element. Its required capacitance varies as a
function of applied line voltage. Additionally, as the power converter’s input
FET switch cycles on and off, the input capacitor must have the ability to
rapidly supply pulses of relatively high current. Therefore, required rms-
ripple-current capabilities of the input capacitor will vary as a function of the
power converter’s load current. Rather than install a large, expensive,
internal capacitor that addresses all possible load conditions, we have
chosen to leave the capacitor out so that you may select a cost-effective
component appropriate to your particular application.
Use the charts below to determine how much input capacitance is required
as a function of input voltage and also to determine the required rms-ripple-
current capabilities of the needed capacitor as a function of output load
current. Note that "low-line" conditions will require proportionally more input
capacitance in order to maintain the required energy levels and that higher
output currents will obviously require higher input currents. Contact DATEL’s
Applications Engineering Group if you have any questions.
UNR-3.3/12000-D5
Minimum Input Capacitor Value vs. VIN @ Full Load
10000
1000
100
4.75
4.80 4.85 4.90 4.95
5.00 5.05 5.10 5.15 5.20 5.25 5.30 5.35 5.40 5.45 5.50
Input Voltage (Volts)
UNR-3.3/8000-D5
Minimum Input Capacitor Value vs. VIN @ Full Load
10000
1000
100
4.75
4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 5.25 5.30 5.35 5.40 5.45 5.50
Input Voltage (Volts)
UNR-3.3/3000-D5
Minimum Input Capacitor Value vs. VIN @ Full Load
1000
100
10
4.75 4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 5.25 5.30 5.35 5.40 5.45 5.50
Input Voltage (Volts)
CIN RMS Ripple Current vs. ILOAD
8
7
6
5
4
3
2
1
0
1 2 3 4 5 6 7 8 9 10 11 12
Output Load Current (Amps)
CIN RMS Ripple Current vs. ILOAD
4
3.5
3
2.5
2
1.5
1
0.5
0
1
2
3
4
5
6
7
8
Output Load Current (Amps)
CIN RMS Ripple Current vs. ILOAD
2
1.75
1.50
1.25
1
0.75
0.50
0.25
0
0.3
0.6 0.9 1.2 1.5
1.8 2.1 2.4
2.7 3.0
Output Load Current (Amps)
4
Share Link: 