YH09T40 40A DC-DC POL Converter
5V to 13.8V Input
0.6V to 3.63V Output
Data Sheet
ZD-02095 Rev. 1.1, 18-Jun-10 www.power-one.com Page 9 of 13
20
25
30
35
40
45
20 30 40 50 60 70
Ambient Temperature (C)
Output Current (A)
NC
100 LFM
200 LFM
300 LFM
400 LFM
Figure 14. Output Current Derating at Vo=1.8Vdc
20
25
30
35
40
45
20 30 40 50 60 70
Ambient Temperature (C)
Output Current (A)
NC
100 LFM
200 LFM
300 LFM
400 LFM
Figure 15. Output Current Derating at Vo=2.5Vdc
20
25
30
35
40
45
20 30 40 50 60 70
Ambient Temperature (C)
Output Current (A)
NC
100 LFM
200 LFM
300 LFM
400 LFM
Figure 16. Output Current Derating at Vo=3.3Vdc
6. Application Information
6.1 Input and Output Impedance
The POL converter should be connected to the DC
power source via low impedance. In many
applications, the inductance associated with the
distribution from the power source to the input of the
converter can affect the stability of the converter.
Internally, the converter includes 60F (low ESR
ceramics) of input capacitance which eliminates the
need for external input capacitance. However, if the
distribution of the input voltage to the POL converter
contains high inductance, it is recommended to add
a 150F decoupling capacitor placed as close as
possible to the converter input pins. A low-ESR
tantalum or POS capacitor connected across the
input pins help ensuring stability of the POL
converter and reduce input ripple voltage.
A 470F POS, tantalum, or ceramic output capacitor
is recommended to improve output ripple and
dynamic response.
It is important to keep low resistance and low
inductance of PCB traces for connecting load to the
output pins of the converter in order to maintain good
load regulation.
6.2 Output Voltage Programming
The output voltage can be programmed from 0.6V to
3.63V by connecting an external resistor R
TRIM
between Trim+ pin (Pin 8) and Trim- pin (Pin 7), as
shown in Figure 17.
Figure 17. Programming Output Voltage With A Resistor
The trim resistor R
TRIM
for a desired output voltage
can be calculated using the following equation:
,
6.0
2.1
OUT
TRIM
V
R
k
Vin
VIN
GND
ON/OFF
VOUT
Power Good
TRIM+
SENSE+
Rload
GND
TRIM-
SENSE-
R
TRIM
4,5
12,13
1,2,3
6
9
8
11
4,5
7
10
YH09T40
