PTB78560A_15 Datasheet, PDF (6/27 Pages) Texas Instruments – 30-W, 24-V/48-V INPUT DC/DC CONVERTERS WITH AUTO-TRACK™ SEQUENCING

PTB78560A, PTB78560B
PTB78560C
SLTS249 – JUNE 2005
www.ti.com
PTB78560C ELECTRICAL CHARACTERISTICS
(Unless otherwise stated, T_A = 25°C, V_I = 24 V, V_O = 12 V, C_O = 100 µF, and I_O = I_Omax)
PARAMETER
TEST CONDITIONS
PTB78560C
MIN
TYP
MAX
I_O
Output current
Over V_I range
V_I
Input voltage range
Over I_O range
Set-point voltage tolerance
I_O Bus
0.1 ⁽¹⁾
18
24
±1 ⁽³⁾
2.5 ⁽²⁾
60
Temperature variation
-40°C ≤ T_A ≤ 85°C
±0.5
Line regulation
V_O
Load regulation
Over V_I range
Over I_O range
±0.2
±1
±0.4
±1
Total output voltage variation Includes set-point, line, load, –40°C ≤ T_A ≤ 85°C
±2
±3 ⁽³⁾
Adjust range
Over V_I range
9
13.2
η
Efficiency
R_SET = 9.09 kΩ, V_O =12 V
R_SET = open, V_O = 9 V
88%
86%
V_O Ripple (peak-to-peak)
20-MHz bandwidth
1
Transient Response
0.1 A/µs load step,
50% to 100%
I_Omax
Recovery time
V_O over/undershoot
100
±150
Track input (pin 5)
Input current
Open-circuit voltage
Track connected to -Sense
–0.48
0
V_O Bus
Referenced to -V_I
Input high voltage (V_IH)
2
Open ⁽⁴⁾
Output enable inputs (pins 2, 3)
Input low voltage (V_IL)
-0.2
0.8
Input low current (I_IL)
–0.8
Standby input current
Pins 2 and 3 open
8
16
I_O Bus Overcurrent threshold
Shutdown, followed by autorecovery
3.75
UVLO Undervoltage lockout
V_I increasing
17
V_I decreasing
16
ƒ_S
Switching frequency
Over V_I range
400
500
600
Internal input capacitance
1
External input capacitance
External output capacitance
Isolation voltage
Between +V_I and –V_I
Between both outputs and V_O COM
Input-output
100
100
1,500
1,500
Isolation capacitance
Input-output
2,000
Isolation resistance
Input-output
10
MTBF Reliability
Telcordia SR-332 50% stress, T_A = 40°C, ground
benign
3.4
UNIT
A
V
%V_O
%V_O
%V_O
%V_O
%V_O
V
%V_O
µs
mV
mA
V
mA
mA
A
V
kHz
µF
µF
µF
Vdc
pF
MΩ
10⁶ Hrs
(1) The converter requires a minimum load current for proper operation. The converter is not damaged when operated under a no-load
condition.
(2) See temperature derating curves for safe operating area (SOA), to determine output current derating at elevated ambient temperatures.
(3) The set-point voltage tolerance is affected by the tolerance and stability of R_SET. The stated limit is unconditionally met if R_SET has a
tolerance of 1%, with 100 ppm/°C temperature stability.
(4) The PEN and NEN enable inputs each have an internal pullup resistor. If the enable feature is not used, the PEN input (pin 2) should be
left open circuit and the NEN input (pin 3) permanently connected to –V_I. A discrete MOSFET or bipolar transistor is recommended for
the enable control. The open-circuit voltage is less than 10 V. See the Application Information for a more detailed description.
6
Submit Documentation Feedback