Datasheet

TPS40055-EP
SGLS310D –JULY 2005–REVISED FEBRUARY 2012 www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
T
A
= –55°C to 125°C, V
IN
= 24 V
dc
, R
T
= 90.9 kΩ, I
KFF
= 150 µA, f
SW
= 500 kHz, all parameters at zero power dissipation
(unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
FB
= 0 V, f
SW
≤ 500 kHz 84% 94%
Maximum duty cycle
V
FB
= 0 V, 500 kHz ≤ f
SW
≤ 1 MHz
(2)
80%
Minimum duty cycle V
FB
≥ 0.75 V 0%
V
KFF
Feed-forward voltage 3.35 3.48 3.7 V
I
KFF
Feed-forward current operating range
(2)
20 1200 µA
SOFT START
I
SS
Soft-start source current 1.2 2.35 3.6 µA
V
SS
Soft-start clamp voltage 3.7 V
t
DSCH
Discharge time C
SS
= 220 pF 1.4 2.2 3.4 µs
t
SS
Soft-start time C
SS
= 220 pF, 0 V ≤ V
SS
≤ 1.6 V 102 150 230 µs
BP10
V
BP10
Output voltage I
OUT
≤ 1 mA 8.9 9.6 10.45 V
ERROR AMPLIFIER
8 V ≤ V
IN
≤ 40 V, T
A
= 25°C 0.698 0.7 0.704
8 V ≤ V
IN
≤ 40 V, 0°C ≤ T
A
≤ 125°C 0.689 0.7 0.717
V
FB
Feedback input voltage V
8 V ≤ V
IN
≤ 40 V, –55°C ≤ T
A
≤ 0.689 0.7 0.719
125°C
G
BW
Gain bandwidth
(3)
2.8 5 MHz
A
VOL
Open loop gain 40 80 dB
I
OH
High-level output source current 1.85 4
mA
I
OL
Low-level output source current 1.95 4
V
OH
High-level output voltage I
SOURCE
= 500 µA 3.1 3.5
V
V
OL
Low-level output voltage I
SINK
= 500 µA 0.2 0.37
I
BIAS
Input bias current V
FB
= 0.7 V 100 220 nA
CURRENT LIMIT
I
SINK
Current limit sink current 7.5 10 12.2 µA
V
ILIM
= 23.7 V, V
SW
= (V
ILIM
– 0.5 V) 300
Propagation delay to output ns
V
ILIM
= 23.7 V, V
SW
= (V
ILIM
– 2 V) 200
t
ON
Switch leading-edge blanking pulse time
(3)
100 ns
t
OFF
Off time during a fault 7 cycle
s
V
ILIM
= 23.6 V, T
A
= 25°C –115 –70 –50
V
ILIM
= 23.6 V, 0°C ≤ T
A
≤ 125°C –155 –38
V
ILIM
= 23.6 V, –55°C ≤ T
A
≤ 125°C –155 –10
V
OS
Offset voltage SW vs ILIM mV
V
ILIM
= 11.6 V, T
A
= 25°C –118 –43
V
ILIM
= 11.6 V, 0°C ≤ T
A
≤ 125°C –160 –45
V
ILIM
= 11.6 V, T
A
= –55°C to 125°C –160 –15
OUTPUT DRIVER
t
LRISE
Low-side driver rise time 48 110
C
LOAD
= 2200 pF ns
t
LFALL
Low-side driver fall time 24 58
t
HRISE
High-side driver rise time 48 105
C
LOAD
= 2200 pF, (HDRV – SW) ns
t
HFALL
High-side driver fall time 36 82
V
OH
High-level output voltage, HDRV I
HDRV
= –0.1 A (HDRV - SW) BOOST BOOST V
–1.9 –1
V
OL
Low-level output voltage, HDRV I
HDRV
= 0.1 A (HDRV - SW) 0.85 V
(3) Ensured by design. Not production tested.
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