UC3842B, 43B UC2842B, 43B
ELECTRICAL CHARACTERISTICS
(VCC = 15 V [Note 2], RT = 10 k, CT = 3.3 nF. For typical values TA = 25°C, for min/max values TA is
the operating ambient temperature range that applies [Note 3], unless otherwise noted.)
UC284XB
Characteristics
ERROR AMPLIFIER SECTION
Voltage Feedback Input (VO = 2.5 V)
Input Bias Current (VFB = 5.0 V)
Open Loop Voltage Gain (VO = 2.0 V to 4.0 V)
Unity Gain Bandwidth (TJ = 25°C)
Power Supply Rejection Ratio (VCC = 12 V to 25 V)
Output Current
Sink (VO = 1.1 V, VFB = 2.7 V)
Source (VO = 5.0 V, VFB = 2.3 V)
Output Voltage Swing
High State (RL = 15 k to ground, VFB = 2.3 V)
Low State (RL = 15 k to Vref, VFB = 2.7 V)
(UC284XB, UC384XB)
(UC384XBV)
CURRENT SENSE SECTION
Current Sense Input Voltage Gain (Notes 4 & 5)
(UC284XB, UC384XB)
(UC384XBV)
Maximum Current Sense Input Threshold (Note 4)
(UC284XB, UC384XB)
(UC384XBV)
Power Supply Rejection Ratio
VCC = 12 V to 25 V, Note 4
Input Bias Current
Propagation Delay (Current Sense Input to Output)
OUTPUT SECTION
Output Voltage
Low State (ISink = 20 mA)
(ISink = 200 mA)
High State
V
VOL
–
–
–
13
–
12
–
–
–
0.1
1.6
–
13.5
–
13.4
0.1
50
50
0.4
2.2
–
–
–
–
1.1
150
150
–
–
–
13
12.9
12
–
–
–
0.1
1.6
1.6
13.5
13.5
13.4
0.1
50
50
0.4
2.2
2.3
–
–
–
1.1
150
150
V
ns
ns
AV
2.85
–
Vth
0.9
–
PSRR
IIB
tPLH(In/Out)
–
–
–
1.0
–
70
– 2.0
150
1.1
–
–
–10
300
0.9
0.85
–
–
–
1.0
1.0
70
– 2.0
150
1.1
1.1
–
–10
300
dB
µA
ns
3.0
–
3.15
–
2.85
2.85
3.0
3.0
3.15
3.25
V
V/V
VFB
IIB
AVOL
BW
PSRR
ISink
ISource
VOH
VOL
2.45
–
65
0.7
60
2.0
– 0.5
5.0
–
–
2.5
– 0.1
90
1.0
70
12
–1.0
6.2
0.8
–
2.55
–1.0
–
–
–
–
–
–
1.1
–
2.42
–
65
0.7
60
2.0
– 0.5
5.0
–
–
2.5
– 0.1
90
1.0
70
12
–1.0
6.2
0.8
0.8
2.58
– 2.0
–
–
–
–
–
V
–
1.1
1.2
V
µA
dB
MHz
dB
mA
Symbol
Min
Typ
Max
UC384XB, XBV
Min
Typ
Max
Unit
(UC284XB, UC384XB)
(UC384XBV)
(ISource = 20 mA) (UC284XB, UC384XB)
(UC384XBV)
(ISource = 200 mA)
VOH
Output Voltage with UVLO Activated
VCC = 6.0 V, ISink = 1.0 mA
Output Voltage Rise Time (CL = 1.0 nF, TJ = 25°C)
Output Voltage Fall Time (CL = 1.0 nF, TJ = 25°C)
UNDERVOLTAGE LOCKOUT SECTION
Startup Threshold (VCC)
UCX842B, BV
UCX843B, BV
Minimum Operating Voltage After Turn–On (VCC)
UCX842B, BV
UCX843B, BV
VOL(UVLO)
tr
tf
Vth
15
7.8
VCC(min)
9.0
7.0
10
7.6
11
8.2
8.5
7.0
10
7.6
11.5
8.2
16
8.4
17
9.0
14.5
7.8
16
8.4
17.5
9.0
V
V
NOTES:
2. Adjust VCC above the Startup threshold before setting to 15 V.
3. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.
Tlow = 0°C for UC3842B, UC3843B
Thigh = +70°C for UC3842B, UC3843B
Tlow =
–25°C for UC2842B, UC2843B
Thigh =
+85°C for UC2842B, UC2843B
Tlow =
–40°C for UC3842BV, UC3843BV
Thigh =
+105°C for UC3842BV, UC3843BV
4. This parameter is measured at the latch trip point with VFB = 0 V.
∆V
Output Compensation
5. Comparator gain is defined as: AV
∆V
Current Sense Input
MOTOROLA ANALOG IC DEVICE DATA
3
MOTOROLA [ MOTOROLA, INC ]
