PARAMETER TEST CONDI TION S UC184xA\UC284xA UC384xA UNITS
MIN. TYP. MAX. MIN. TYP. MAX.
Erro r Am p Sectio n
Input Voltage VPIN 1 = 2. 5 V 2. 4 5 2.5 0 2.5 5 2. 4 2 2. 5 0 2.58 V
Input Bias Current -0.3 -1 -0.3 -2 µA
AVOL 2 ≤ VO ≤ 4V 65 90 65 90 dB
Un ity Gain Bandwidt h TJ = 25°C (Note 2) 0.7 1 0.7 1 MHz
PSRR 12 ≤ VCC ≤ 25V 6070 6070 dB
Output Sink Current VPIN 2 = 2. 7V, VPIN 1 = 1.1V 2 6 2 6 m A
Output Source Current VPIN 2 = 2.3V, VPIN 1 = 5V -0.5 -0.8 -0.5 -0.8 mA
VOUT High VPIN 2 = 2.3V, RL = 15k to gr ound 5 6 5 6 V
VOUT Low VPIN 2 = 2.7V, RL = 15k to Pin 8 0.7 1.1 0.7 1.1 V
Current Sense Section
Ga in (Note 3, Not e 4) 2.8 5 3 3.15 2.8 5 3 3.15 V/V
Max imum Input Signal V PIN 1 = 5V ( No t e 3) 0.9 1 1. 1 0. 9 1 1. 1 V
PSRR 12 ≤ VCC ≤ 25V (Note 3) 70 70 dB
Input Bias Current -2 -10 -2 -10 µA
Delay to O u tput V PIN 3 = 0 to 2V (Note 2) 150 300 150 300 ns
Ou tpu t Secti on
Output Low Level ISINK = 20mA 0.1 0.4 0.1 0.4 V
ISINK = 200m A 1 5 2.2 15 2.2 V
Output High Level ISOURCE = 20 mA 1 3 13. 5 13 13.5 V
ISOURCE = 200mA 1 2 13. 5 12 13. 5 V
Rise Ti me TJ = 25 °C, C L = 1nF (Not e 2) 50 150 50 150 ns
Fall Time TJ = 25 °C, CL = 1nF (Note 2) 5 0 150 50 150 n s
UVLO Saturation VCC = 5V, ISINK = 10 mA 0. 7 1. 2 0. 7 1. 2 V
Un der -Vol t age Lo ckou t Secti on
Start Threshold x842A/4A 15 16 17 14.5 16 17.5 V
x843A/5A 7.8 8.4 9.0 7.8 8.4 9.0 V
Min. Oper at io n Voltage Af te r x842A/4 A 9 1 0 1 1 8.5 10 11.5 V
Turn On x843A/5A 7.0 7.6 8.2 7.0 7.6 8.2 V
PWM Section
Max imum Duty Cycle x842A/3A 94 96 100 94 96 100 %
x844A/5A 47 48 50 47 48 50 %
Minimum Duty Cycle 0 0 %
T ota l Standb y Current
Start-Up Current 0.3 0. 5 0.3 0.5 mA
Operating Supply Current VPIN 2 = V PIN 3 = 0V 11 17 11 17 mA
VCC Zener Voltage ICC = 25mA 30 34 30 34 V
UC1842A/3A/4A/5A
UC2842A/3A/4A/5A
UC3842A/3A/4A/5A
Note 2: These par am et ers, alt hou gh gua ran teed, are not 100%
te st ed in production.
Note 3: Parame te r measu red at trip poin t of latch with V
PIN2
= 0.
Note 4: Gain def ined as : A
= ∆
V
PIN
1
∆
V
PIN
3
; 0
≤
V
PIN 3
≤
0. 8 V.
Note 5 : Adjust V
CC
above the st ar t thresho ld before setting at
15V.
Note 6: O ut put frequ ency equals oscillator frequ ency for the
UC1842A and UC1843 A. Outpu t frequen cy is one half
osc illat or frequency for the UC1 844A and UC1845A.
Not e 7: "Tem pe r at u re sta b i lit y, sometim es re fe rr ed to as a ve r ag e
tem per ature coef f icie nt, is describe d by t he equ atio n:
Temp
Stability
=
V
REF
(
max
) −
V
REF
(
min
)
T
J
(
max
) −
T
J
(
min
)
.
V
REF
(m ax) and V
REF
(min) ar e the m axim um & mini-
mum refere nce voltag e me asur ed ov er t he ap pro priat e
temp era tu re range . Note that the ext r emes in volt age
do not necessa rily occur at th e extremes in tem pera-
ture."
Note 8: This param et er is measure d w ith R
T
= 10k
Ω
to V
REF
.
This contributes appr oximately 300
µ
A of current to t h e
measuremen t. The total cur re nt flowing into the R
T
/C
T
pin will be approximately 300
µ
A higher than the meas-
ured value.
ELECTRICAL CHARACTERISTICS (cont.) U nless otherwise stated, these specifications apply for -55°C ≤ TA ≤ 125°C fo r
the UC184xA; -40°C ≤ TA ≤ 85 °C for the UC284xA; 0 ≤ TA ≤ 70 °C for the UC384xA; VCC = 15V (Note 5); RT = 10k; CT = 3.3nF; TA = TJ;
Pin numbers re fe r to DIL-8.
3