Datasheet

   
   
SLUS419C − AUGUST 1999 − REVISED NOVEMBER 2001
4
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electrical characteristics T
A
= 0°C to 70°C for the UCC3850X, –40°C to 85°C for the UCC2850X,
T
A
= T
J
, VCC = 12 V, RT = 22 kΩ, CT = 330 pF (unless otherwise noted)
voltage reference
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Input voltage
T
A
= 0°C to 70°C 7.387 7.500 7.613 V
Input voltage
T
A
= –40°C to 85°C 7.35 7.50 7.65 V
Load regulation I
REF
= −1 mA to −2 mA, See Note 2 0 10 mV
Line regulation VCC = 10.8 V to 15 V, See Note 3 0 10 mV
Short circuit current VREF = 0V −20 –25 −50 mA
oscillator
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Frequency, initial accuracy T
A
= 25°C 85 100 115 kHz
Frequency, voltage stability VCC = 10.8 V to 15 V −1% 1%
Frequency, total variation Line, Temp 80 120 kHz
Ramp peak voltage 4.5 5 5.5 V
Ramp amplitude voltage (peak to peak) 3.5 4 4.5 V
peak current limit
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
PKLMT reference voltage –15 0 15 mV
PKLMT propagation delay 150 300 500 ns
multiplier
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
I
MOUT
, high-line low-power output current
I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 1.25 V,
0°C ≤ T
A
≤ 85°C
0 –6 −20
I
MOUT
, high-line low-power output current
I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 1.25 V,
–40°C ≤ T
A
≤ 85°C
0 –6 −23
A
I
MOUT
, high-line high-power output current I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 5 V −70 –90 −105
µA
I
MOUT
, low-line low-power output current I
AC
= 150 µA, VFF = 1.4 V, VAOUT = 1.25 V −10 –19 −50
I
MOUT
, low-line high-power output current I
AC
= 150 µA, VFF = 1.4 V, VAOUT = 5 V −268 –300 −345
I
MOUT
, IAC-limited output current I
AC
= 150 µA, VFF = 1.3 V, VAOUT = 5 V −250 –300 −400
Gain constant (K) I
AC
= 300 µA, VFF = 2.8 V, VAOUT = 2.5 V 0.5 1 1.5
1/V
I
AC
= 150 µA, VFF = 1.4 V, VAOUT = 0.25 V 0 –2
1/V
I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 0.25 V 0 –2 µA
I
MOUT
, zero current
I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 0.5 V,
0°C ≤ T
A
≤ 85°C
0 –3 µA
I
AC
= 500 µA, VFF = 4.7 V, VAOUT = 0.5 V,
−40°C ≤ T
A
≤ 85°C
0 –3.5 µA
Power limit (I
MOUT
× V
FF
) I
AC
= 150 µA, VFF = 1.4 V, VAOUT = 5 V −375 –420 −485 µW
zero power
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Zero power comparator threshold Measured on VAOUT 0.175 0.330 0.500 V
NOTES: 1. Ensured by design. Not production tested.
2. See Figure 6 for reference variation.
3. See Figure 5 for reference variation for VCC < 10.8 V .