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ELECTRICAL CHARACTERISTICS
SLTS219F – FEBRUARY 2004 – REVISED MARCH 2007
(Unless otherwise stated, TA = 25°C, VI = 48 V, CI = 0 F, CO = 0 F, IO1 = IO2 = 3.25 A maximum)
PTB4851xC
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
PO
Output Power
Total output power from VO1 or VO2
0
66(1)
W
IO1 or IO2
Output Current
Over VI range, IO1 ≤ 0.1 A or IO2 ≤ 0.1 A
0
2.2(2)
A
IO1 - IO2
Output Load Imbalance
IO1 ≤ 0.1 A or IO2 ≤ 0.1 A
0
1(3)
A
Includes set point, line, load, IO1 - IO2 ≤ 0.1 A,
VO1 or VO2
Output Voltage
14.5(2)
15 15.5(2)
V
–40
°C ≤ T
A ≤ 85°C
–40
°C ≤ T
A ≤ 85°C, IO1 ≤ 0.1 A or IO2 ≤ 0.1
VO1 or VO2
±1
ΔRegtemp
Temperature Variation
%VO
A
ΔRegline
Line Regulation
Over VI range, balanced load
VO1 or VO2
±0.05
±0.5
%VO
ΔRegload
Load Regulation
Over IO1 or IO2 range, balanced load
VO1 or VO2
±0.1
±1
%VO
η
Efficiency
IO1 = IO2
90%
Vr
VO Ripple (pk-pk)
20 MHz bandwidth, CO = 10 F tantalum capacitor
50
100(4)
mVpp
ttr
0.1 A/
s load step, 50% to 75% I
O1 or IO2 maximum
30
s
Transient Response
ΔVtr
VO1 or VO2 overshoot/undershoot
±1
%VO
IOtrip
Over Current Threshold
VI = 36 V, reset followed by auto-recovery
2.45
3
3.85
A
IO1(pk) IO2(pk)
4.5
A
Short Circuit Current
Continuous overcurrent trip, IO1 = IO2
Duty
10%
VO1(adj) ,
Output Voltage Adjust
VO1 and VO2 adjust simultaneously
7.2
16.7
V
VO2(adj)
Range
f S
Switching Frequency
Over VI and IO ranges
440
480(5)
520
kHz
VI on
VI increasing
33
Under-Voltage Lockout
V
VI off
VI decreasing
32
On/Off Enable (pin 3)
Referenced to –VI (pin 4)
VIH
High-level input voltage
3.6
75(6)
V
VIL
Low-level input voltage
–0.2
0.8
IIL
Low-level input current
–1
mA
II standby
Standby Input Current
Pin 3 open circuit
2
mA
tON
Start-up Time
IO1 ≤ 1 A or IO2 ≤ 1 A, VO1 or VO2 or rising 0 to 0.95 (typ)
6
12
18
ms
CI
Internal Input Capacitance
3
F
External Output
3000(7
CO
Capacitance from either output to COM (pin 6)
0
F
Capacitance
)
Per Telcordia SR-332 50% stress,
MTBF
Reliability
2.8
106 hrs
TA = 40°C, ground benign
(1)
See Safe Operating Area curves or contact the factory for the appropriate derating.
(2)
Under balanced load conditions, load current flowing out of VO1 is balanced to within ±0.1 A of that flowing into VO2.
(3)
A load imbalance is the difference in current flowing from VO1 to VO2. The module can operate with a higher imbalance but with reduced
specifications.
(4)
Output voltage ripple is measured with a 10-
F tantalum capacitor connected from V
O1 (pin 5) or VO2 (pin 8), to COM (pin 6).
(5)
This is the free-running frequency. The module can be made to synchronize with the PTB48500 when both modules are used together
in a system.
(6)
The On/Off Enable (pin 3) has an internal pull-up and may be controlled with an open-collector (or open-drain) transistor. The input is
diode protected and may be connected to VI. The open-circuit voltage is 5 V maximum. If it is left open circuit the converter operates
when input power is applied.
(7)
Electrolytic capacitors with very low equivalent series resistance (ESR) may induce instability when used on the output. Consult the
factory before using capacitors with organic, or polymer-aluminum type electrolytes.
Copyright 2004–2007, Texas Instruments Incorporated
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