Datasheet
ELECTRICAL CHARACTERISTICS
TPS40077
SLUS714D – JANUARY 2007 – REVISED APRIL 2009 .....................................................................................................................................................
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T
A
= – 40 ° C to 85 ° C, V
IN
= 12 V
dc
, R
T
= 90.9 k Ω , I
KFF
= 300 µ A, f
SW
= 500 kHz, all parameters at zero power dissipation
(unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
INPUT SUPPLY
V
VDD
Input voltage range, VIN 4.5 28 V
OPERATING CURRENT
I
VDD
Quiescent current Output drivers not switching 2.5 3.5 mA
LVBP
V
LVBP
Output voltage T
A
= T
J
= 25 ° C 3.9 4.2 4.5 V
OSCILLATOR/RAMP GENERATOR
f
OSC
Accuracy 450 500 550 kHz
V
RAMP
PWM ramp voltage
(1)
V
PEAK
– V
VAL
2 V
V
RT
RT voltage 2.23 2.4 2.58 V
t
ON
Minimum output pulse time
(1)
C
HDRV
= 0 nF 150 ns
V
FB
= 0 V, 100 kHz ≤ f
SW
≤ 500 kHz 84% 93%
Maximum duty cycle
V
FB
= 0 V, f
SW
= 1 MHz 76% 93%
V
KFF
Feed-forward voltage 0.35 0.4 0.45 V
I
KFF
Feed-forward current operating range
(1)
20 1100 µ A
SOFT START
I
SS
Charge current 7 12 17 µ A
t
DSCH
Discharge time C
SS
= 3.9 nF 25 75 µ s
C
SS
= 3.9 nF, V
SS
rising from 0.7 V to
t
SS
Soft-start time 210 290 500 µ s
1.6 V
Turnon threshold 310 365 420
V
SSSD
Shutdown threshold 225 275 325 mV
V
SSSDH
Shutdown threshold hysteresis 35 150
DBP
V
DD
> 10 V 7 8 9
V
DBP
Output voltage V
V
DD
= 4.5 V, I
OUT
= 25 mA 4 4.3
ERROR AMPLIFIER
T
J
= 25 ° C 0.698 0.7 0.704
V
FB
Feedback regulation voltage total variation 0 ° C ≤ T
J
≤ 85 ° C 0.69 0.7 0.707 V
– 40 ° C ≤ T
J
≤ 85 ° C 0.69 0.7 0.715
V
SS
Soft-start offset from VSS
(1)
Offset from V
SS
to error amplifier 1 V
G
BW
Gain bandwidth
(1)
5 10 MHz
A
VOL
Open-loop gain 50 dB
I
SRC
Output source current 2.5 4.5
mA
I
SINK
Output sink current 2.5 6
I
BIAS
Input bias current V
FB
= 0.7 V – 250 0 nA
(1) Ensured by design. Not production tested.
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