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TPS54350
SLVS456C − OCTOBER 2003 − REVISED OCTOBER 2004
RECOMMENDED OPERATING CONDITIONS
MIN
Input voltage range, VI
Operating junction temperature, TJ
4.5
−40
NOM
MAX
20
125
UNIT
V
°C
ELECTRICAL CHARACTERISTICS
TJ = –40°C to 125°C, VIN = 4.5 V to 20 V (unless otherwise noted)
PARAMETER
SUPPLY CURRENT
IQ
Quiescent current
Start threshold voltage
VIN
Stop threshold voltage
Hysteresis
UNDER VOLTAGE LOCK OUT (UVLO PIN)
Start threshold voltage
UVLO
Stop threshold voltage
Hysteresis
BIAS VOLTAGE (VBIAS PIN)
VBIAS
Output voltage
IVBIAS = 1 mA, VIN
≥
12 V
IVBIAS = 1 mA, VIN = 4.5 V
TJ = 25°C
7.5
4.4
0.888
0.882
RT Grounded
Internally set PWM switching frequency
Externally set PWM switching frequency
RT Open
RT = 100 kΩ (1% resistor to AGND)
200
400
425
7.8
4.47
0.891
0.891
250
500
500
200
5
180
100
360
2.5
0.6
0.8
2.3
Percentage of programmed frequency
−10%
225
10%
770
kHz
8.0
4.5
0.894
0.899
300
600
575
500
10
kHz
kHz
ns
ns
°
ns
ns
V
V
V
V
V
1.02
1.20
1.10
100
1.24
V
V
mV
3.69
Operating Current, PH Pin open,
No external low side MOSFET, RT = Hi-Z
Shutdown, ENA = 0 V
5
1.0
4.32
3.97
350
4.49
mA
mA
V
V
mV
TEST CONDITIONS
MIN
TYP
MAX
UNIT
REFERENCE SYSTEM ACCURACY
V
V
Reference voltage
OSCILLATOR (RT PIN)
FALLING EDGE TRIGGERED BIDIRECTIONAL SYNC SYSTEM (SYNC PIN)
SYNC out low-to-high rise time (10%/90%) (1)
25 pF to ground
SYNC out high-to-low fall time (90%/10%) (1)
Falling edge delay time (1)
Minimum input pulsewidth (1)
Delay (falling edge SYNC to rising edge PH) (1)
SYNC out high level voltage
SYNC out low level voltage
SYNC in low level threshold
SYNC in high level threshold
SYNC in frequency range (1)
(1) Ensured by design, not production tested.
25 pF to ground
Delay from rising edge to rising edge of
PH pins, see Figure 19
RT = 100 kΩ
RT = 100 kΩ
50 kΩ resistor to ground, no pullup
resistor
3
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