
4
UC1870 -1/ -2
UC2870 -1/ -2
UC3870 -1/ -2
ELECTRICAL CHARACTERISTICS:
Unless otherwise stated these specifications apply for T
A
= –55°C to +125°C for
UC1870X; –25°C to +85°C for UC2870X; 0°C to +70°C for UC3870X; VCC = 12V, C
T
= 680pF, C
CAP
= 1 F; C
BOOT
= 0.1 F,
T
A
= T
J
.
PARAMETER
TEST CONDITIONS
Oscillator Section
Initial Accuracy
T
A
= 25°C
Voltage Stability
VCC = 12V to 18V
Total Variation
Line, Temperature
Ramp Amplitude (p-p)
T
A
= 25°C
Ramp Valley Voltage
T
A
= 25°C
Sleep/Soft Start/Bootstrap Section
Sleep Threshold
Measured on SS, T
A
= 25°C
SS Charge Current
V
SS
= 2.5V
SS Discharge Current
V
SS
= 2.5V
Bootstrap Regulation Voltage
UCX870-2, Low Driver ON
UCX870-1, Low Driver ON
Bootstrap Refresh Voltage
UCX870-2, V
CAOUT
> V
CTpeak
UCX870-1, V
CAOUT
> V
CTpeak
High Side Driver Output Section
Output High Voltage
I
OUT
= –50mA, BOOT = 23V
Output Low Voltage
I
OUT
= 50mA
I
OUT
= 10mA
Output Low (UVLO)
I
OUT
= 50mA, VCC = 0V
Output Rise Time
C
OUT
= 1nF
Output Fall Time
C
OUT
= 1nF
Low Side Driver Output Section
Output High Voltage
I
OUT
= –50mA, V
CAP
= 11V
Output Low Voltage
I
OUT
= 50mA
I
OUT
= 10mA
Output Low (UVLO)
I
OUT
= 50mA, VCC = 0V
Output RISE/FALL Time
C
LOAD
= 1nF
Output FALL Time
C
OUT
= 1nF
X10 Amplifier Section
Gain
V
ISNS
±
V
ISNS
= 20mV to 80mV
Slew Rate Rising
T
A
= 25°C
Slew Rate Falling
T
A
= 25°C
Input Resistance
T
A
= 25°C
MIN
TYP
MAX
UNITS
85
100
1
115
1.5
120
2.85
kHz
%
kHz
V
V
80
2.48
0.86
2.7
0.95
0.25
4
0.5
9.5
6
7
2.7
0.6
6
0.8
10.2
7.5
8
3.5
0.8
10
V
A
mA
V
V
V
V
12.5
9
9
4
21
22.2
1
300
0.9
40
30
V
V
2.2
500
1.5
160
100
mV
V
ns
ns
8.8
9.5
1
300
0.9
40
30
V
V
2.2
500
1.5
160
100
mA
V
ns
ns
9.2
1
2
60
10
1.4
3.5
100
10.4
V/V
V/ s
V/ s
k/
165