Datasheet

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