Product # BQ55090QPA40

Phone 1-888-567-9596

www.synqor.com

Doc.# 005-2BQ559K Rev. A

3/6/07

Page 6

Input:

Input:

Output:

Output:

Current:

Current:

ackage:

35-55 V

35-55 V

9.6 V

9.6 V

43 A

43 A

Quarter-brick

Quarter-brick

T

pecification

0

5

10

15

20

25

30

35

40

45

25

40

55

70

85

Ambient Air Temperature (ºC)

400 LFM (2.0 m/s)

300 LFM (1.5 m/s)

200 LFM (1.0 m/s)

100 LFM (0.5 m/s)

Figure 7: Maximum output power derating curves vs. ambient air tem-

perature for airflow rates of 100 LFM through 400 LFM with air flow-

ing from output to input (nominal input voltage).

Figure 8: Thermal plot of converter at 43 amp load current (400W)

converter from output to input (nominal input voltage).

Figure 9: Turn-on transient at half load (resistive load) and 3mF output

capacitance (2.0ms/div). Input voltage pre-applied. Channel 1: Vout

(2V/div). Channel 2: ON/OFF input (2V/div).

Figure 10: Turn-on transient at zero load and 3mF output capacitance

(2.0ms/div). Input voltage pre-applied. Channel 1: Vout (2V/div).

Channel 2: ON/OFF input (2V/div).

50% of Iout(max); dI/dt = 0.1A/µ s). Load cap: 15µ F, 100 m

W ESR tantalum cap

and 1µ F ceramic cap. Top trace: Vout (200mV/div), Bottom trace: Iout (10A/div).

Terminal Ripple Current (Figure 13), Input Reflected Ripple Current

(Figure 14) and Output Voltage Ripple (Figure 15).

source

impedance

DC/DC

Converter

See Fig. 14

See Fig. 13

See Fig. 15

ceramic

capacitor

15 µF,

450mW ESR

tantalum

capacitor

47 µF,

<1W ESR

electrolytic

capacitor

i

S

i

C