Datasheet

ELECTRICAL CHARACTERISTICS
UC2843A-Q1
www.ti.com ........................................................................................................................................................................................................ SGLS384 – MAY 2008
T
A
= – 40 ° C to 125 ° C, V
CC
= 15 V
(1)
, R
T
= 10 k Ω , C
T
= 3.3 nF, T
A
= T
J
(unless otherwise stated)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Reference Section
Output voltage T
J
= 25 ° C, I
O
= 1 mA 4.95 5.0 5.05 V
Line regulation voltage V
IN
= 12 V to 25 V 6 20 mV
Load regulation voltage I
O
= 1 mA to 20 mA 6 25 mV
Temperature stability
(2) (3)
0.2 0.4 mV/ ° C
Total output variation voltage Line, load, temperature 4.9 5.1 V
Output noise voltage f = 10 Hz to 10 kHz T
J
= 25 ° C 50 µ V
Long term stability 1000 hours T
A
= 125 ° C 5 25 mV
Output short-circuit current – 30 – 100 – 180 mA
Oscillator Section
Initial accuracy
(4)
T
J
= 25 ° C 47 52 57 kHz
Voltage stability V
CC
= 12 V to 25 V 0.2 1 %
Temperature stability T
A
= MIN to MAX 5 %
Amplitude peak-to-peak V pin 7 1.7 V
T
J
= 25 ° C 7.8 8.3 8.8
Discharge current
(5)
V pin 7 = 2 V mA
T
J
= Full range 7.5 8.8
Error Amplifier Section
Input voltage COMP = 2.5 V 2.45 2.5 2.55 V
Input bias current – 0.3 – 1 µ A
Open loop voltage gain (AVOL) V
O
= 2 V to 4 V 65 90 dB
Unity gain bandwidth
(3)
T
J
= 25 ° C 0.7 1 MHz
PSRR V
CC
= 12 V to 25 V 60 70 dB
Output sink current FB = 2.7 V, COMP = 1.1 V 2 6 mA
Output source current FB = 2.3 V, COMP = 5 V – 0.5 – 0.8 mA
VOUT high FB = 2.3 V, RL = 15 k Ω to GND 5 6 V
VOUT low FB = 2.7 V, RL = 15 k Ω to V
REF
0.7 1.1 V
Current Sense Section
Gain
(6) (7)
2.85 3 3.15 V/V
Maximum input signal
(6)
COMP = 5 V 0.9 1 1.1 V
PSRR
(6)
V
CC
= 12 V to 25 V 70 dB
Input bias current – 2 – 10 µ A
Delay to output
(3)
I
SENSE
= 0 V to 2 V 150 300 ns
(1) Adjust V
CC
above the start threshold before setting at 15 V.
(2) Temperature stability, sometimes referred to as average temperature coefficient, is described by the equation:
Temperature Stability = (V
REF
(max) – V
REF
(min))/(T
J
(max) – T
J
(min)). V
REF
(max) and V
REF
(min) are the maximum and minimum
reference voltage measured over the appropriate temperature range. Note that the extremes in voltage do not necessarily occur at the
extremes in temperature.
(3) Specified by design.
(4) Output frequency equals oscillator frequency for the UC2843A.
(5) This parameter is measured with R
T
= 10 k Ω to V
REF
. This contributes approximately 300 µ A of current to the measurement. The total
current flowing into the R
T
/R
C
pin is approximately 300 µ A higher than the measured value.
(6) Parameter measured at trip point of latch with V
FB
at 0 V.
(7) Gain is defined by: A = Δ V
COMP
/ Δ V
SENSE
; 0 ≤ V
SENSE
≤ 0.8 V.
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Product Folder Link(s): UC2843A-Q1