Product # BQ55090QTA27

Phone 1-888-567-9596

www.synqor.com

Doc.# 005-2BQ559J Rev. C

04/02/09

Page 3

Input:

Output:

Current:

Package:

36-55 V

9.6 V

27A

Quarter-brick

Technical Specification

BQ55 FAMILY ELECTRICAL CHARACTERISTICS

Ta = 25 °C, airflow rate = 300 LFM, Vin = 48 V dc unless otherwise noted; full operating temperature range is -40 °C to +100 °C ambient temperature

with appropriate power derating. Specifications subject to change without notice.

Parameter

Min.

Typ.

Max.

Units Notes & Conditions

ABSOLUTE MAXIMUM RATINGS

Input Voltage

Non-Operating

0

60

V

Continuous

Operating

36

48

55

V

Continuous

Operating Transient Protection

N/A

V

100 ms transient, square wave

Isolation Voltage

Input to Output

2000

V

Operating Temperature

-40

100

°C

Storage Temperature

-55

125

°C

Voltage at ON/OFF input pin

-2

18

V

INPUT CHARACTERISTICS

Operating Input Voltage Range

36

48

55

V

Input Under-Voltage Lockout

Turn-On Voltage Threshold

34.3

V

Turn-Off Voltage Threshold

32

V

Lockout Voltage Hysteresis

2.4

V

Input Over-Voltage Shutdown

V

Turn-On Voltage Threshold

59.2

V

Turn-Off Voltage Threshold

56.9

V

Maximum Input Current

8.5

A

No-Load Input Current

110

mA

Disabled Input Current

15.0

30.0

mA

Input Reflected-Ripple Current

10

20

mA

RMS through 10µH inductor

Input Terminal-Ripple Current

140

mA

RMS, full load

Recommended Input Fuse (see Note 1)

20

A

Fast blow external fuse recommended

Recommended External Input Capacitance

47

µF

Typical ESR 0.1-0.2 Ω

Input Filter Component Values (C\L\C)

1\6.6

µH\µF Internal values; see Figure E

OUTPUT CHARACTERISTICS

Output Voltage Set Point

9.6

V

Output Voltage Regulation

Over Line

40\3.8

%\V

Over Load

5.2\500

%\mV

Over Temperature

2\200

%\mV

Total Output Voltage Range

6.550

11.000

V

Over sample, line, load, temperature & life

Output Voltage Ripple and Noise

20 MHz bandwidth; see Note 2

Peak-to-Peak

50

90

mV

Full load

RMS

20

mV

Full load

Operating Output Current Range

0

36

A

at 7.2 Vout, 36Vin; Subject to thermal derating

Output DC Current-Limit Inception

48

A

36Vin, Output Voltage 10% Low

Output DC Current-Limit Shutdown Voltage

5

V

Back-Drive Current Limit while Disabled

10

mA

Negative current drawn from output

Maximum Output Capacitance

3,000

µF

9.6Vout at 27 A Resistive Load

DYNAMIC CHARACTERISTICS

Output Voltage during Load Current Transient

Step Change in Output Current (0.1 A/µs)

200

mV

50% to 75% to 50% Iout max

Settling Time

100

µs

To within 1% Vout nom

Turn-On Transient

Turn-On Time (with 3mF output capacitance)

2

3

ms

Full load, Vout=90% nom.

Start-Up Inhibit Time

200

ms

-40 °C to +125 °C; Figure F

Output Voltage Overshoot

0

%

3 mF load capacitance