ELECTRICAL CHARACTERISTICS:
PIN DESCRIP TI ONS
A, B: Signal and power input pins. Connect these pins to
the secondary of the transformer driven by UC1726.
CLAMP: Analog programming pin for intermediate drive
level to be used at turn on or in response to a desaturation event. Requires a bypass capacitor to COM.
COM: Self generated common for bipolar supply. This
pin will be 16.5V below PV
CC.
D
SA T + , DSAT-: Inputs to the desaturation comparator. De-
saturation is detected when D
SA T+ is greater than D SAT-.
ENBL: Negative true enable input. Tie to VCC to disable
the chip. Connect to COM to enable the chip. If the
ENBL
pin is used as the primary input to the chip, connect B to
V
CC and A to V EE.
FRC: Fault Resistor and Capacitor. Programs the duration that OUT will be held at CLAMP potential during a desaturation event before it is driven fully low. Also sets the
period of time tha t OUT will be held low before allowing it
to be driven high again.
FRPLY: Fault Reply pin. Open coll ector output. Normally
connected to V
EE. When desaturation is detected, the pin
opens.
OUT: Gate drive output. Connect to gate of IGBT with a
series damping resistor greater than 3 ohms.
TRC: Timing Resistor and Capacitor. Programs the dura-
tion that OUT will be held at CLAMP potential and the period of time the desaturation comparator will be ignored
during the rising edge.
V
CC: Positive supply voltag e. Bypass to COM with a low
ESL/ESR 1µF capacitor.
V
EE: Negative supply voltage. Bypass to COM with a low
ESL/ESR 1µF capacitor.
PV
EE: Output driver negative supply. Connect to VEE
with a 3.3 ohm resistor and bypass to COM with a low
ESL/ESR 1µF capacitor.
PV
CC: Output driver positive supply. Connect to VCC with
a 3.3 ohm resistor and bypass to COM with a low
ESL/ESR 1µF capacitor.
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Power Input Receivers
Forward Diode Dro p I
F = 50mA 0.5 0.65 V
I
F = 500mA 1.2 2 V
V
CC Regulator
V
CC 25 ≤ (VCC - VEE) ≤ 36V,I(COM) ≤ 15mA 15.5 16.5 17.5 V
Hysteresis Com par at or
Input Open Circuit Voltag e (Measured with respe ct to V
EE)12V
Input Impedance 100 kΩ
Hysteresis 44 47 50 V
Enable Input
High Level Input Voltage 12 V
Low Level Input Volta ge 5V
Input Bias Cur ren t
ENBL = COM −460 −900 µA
Output Driver
Saturation to V
CC I(OUT ) = -2 0 mA 1.7 2.3 V
Saturation to V
CC I(OUT ) = -5 0 0m A 2 2.5 V
Saturation to V
EE I(OUT) = 20mA 2 3 V
Saturation to V
EE I(OUT) = 500mA 2.4 3.6 V
Unless otherw ise stat ed, these sp ecif icat io ns apply for TA = − 55°C to 125°C for the
UC1727, TA = −40°C to 85°C for the UC2727, TA = 0°C to 70° C for the UC3727,
R(TRC) = 54.9k, C(TRC) = 180pF , R(FRC) = 309K, C(FRC) = 200pF, VCC - VEE =
25V, CLAMP = 9V, TA = TJ, and all voltage s are mea sur ed with respect to COM.