UC1846/7
UC2846/7
UC3846/7
(Unless otherwise stated, these specifications apply for TA=-55°C to +125°C for UC1846/7;
-40°C to +85°C for the UC2846/7; and 0°C to +70°C for the UC3846/7; VIN=15V, RT=10k,
CT=4.7nF, TA=TJ.)
ELECTRICAL
CHARACTERISTICS (cont.)
UC1846/UC1847
UC3846/UC3847
PARAMETER
TEST CONDITIONS
UC2846/UC2847
MIN. TYP. MAX. MIN. TYP. MAX. UNITS
Shutdown Terminal Section (cont.)
Maximum Non-Latching
Current (IPIN 1)
(Note 7)
1.5
0.8
1.5
0.8
mA
ns
Delay to Outputs
TJ=25°C (Note 2)
300
600
300
600
Output Section
Collector-Emitter Voltage
40
40
V
µA
V
Collector Leakage Current VC=40V (Note 5)
200
0.4
2.1
200
0.4
2.1
Output Low Level
ISINK=20mA
0.1
0.4
0.1
0.4
ISINK=100mA
V
Output High Level
ISOURCE=20mA
13
12
13.5
13.5
50
13
12
13.5
13.5
50
V
ISOURCE=100mA
V
Rise Time
Fall Time
CL=1nF, TJ=25°C (Note 2)
CL=1nF, TJ=25°C (Note 2)
300
300
300
300
ns
ns
50
50
Under-Voltage Lockout Section
Start-Up Threshold
7.7
8.0
7.7
8.0
V
V
Threshold Hysteresis
Total Standby Current
Supply Current
0.75
0.75
17
21
17
21
mA
Note 2. These parameters, although guaranteed over the recommended operating conditions, are not 100% tested in production.
Note 3. Parameter measured at trip point of latch with VPIN 5 = VREF, VPIN 6 = 0V.
∆VPIN 7
∆VPIN 4
Note 4. Amplifier gain defined as: G =
;
VPIN4 = 0 to 1.0V
Note 5. Applies to UC1846/UC2846/UC3846 only due to polarity of outputs.
Note 6. Current into Pin 1 guaranteed to latch circuit in shutdown state.
Note 7. Current into Pin 1 guaranteed not to latch circuit in shutdown state.
APPLICATIONS DATA
Oscillator Circuit
ID
3.6
RT (kΩ)
Output deadtime is determined by the external capacitor, CT, according to the formula: τd (µs) =145CT (µf )
.
ID -
ID = Oscillator discharge current at 25°C is typically 7.5.
For large values of RT: τd (µs) ≈145CT (µf ).
2.2
Oscillator frequency is approximated by the formula:fT (kHz) ≈
.
RT (kΩ) •CT (µf )
4
TI [ TEXAS INSTRUMENTS ]
