NCP1589D
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3
PIN FUNCTION DESCRIPTION
Pin No. Symbol Description
1 BOOT Supply rail for the floating top gate driver. To form a boost circuit, use an external diode to bring the desired
input voltage to this pin (cathode connected to BOOT pin). Connect a capacitor (C
BOOT
) between this pin
and the LX pin. Typical values for C
BOOT
range from 0.1 mF to 1 mF. Ensure that C
BOOT
is placed near the
IC.
2 LX Switch node pin. This is the reference for the floating top gate driver. Connect this pin to the source of the
top MOSFET. Also used for low side MOSFET R
DS(on)
current detection and diode emulation.
3 UG Top gate MOSFET driver pin. Connect this pin to the gate of the top N−channel MOSFET.
4 LG Bottom gate MOSFET driver pin. Connect this pin to the gate of the bottom N−channel MOSFET. Also used
to set the overcurrent limit.
5 GND IC ground reference. All control circuits are referenced to this pin. Connect to FLAG.
6 VCC
Supply rail for the internal circuitry. Operating supply range is 4.5 V to 13.2 V. Decouple with a 1 mF capaci-
tor to GND. Ensure that this decoupling capacitor is placed near the IC. Also low−side MOSFET drive volt-
age.
7 COMP/DISB Compensation Pin. This is the output of the error amplifier (EA) and the non−inverting input of the PWM
comparator. Use this pin in conjunction with the FB pin to compensate the voltage−control feedback loop.
Pull this pin low for disable.
8 FB This pin is the inverting input to the error amplifier. Use this pin in conjunction with the COMP pin to com-
pensate the voltage−control feedback loop. Connect this pin to the output resistor divider (if used) or directly
to V
out
.
9 VORPM Output voltage information for RPM threshold
10 PGOOD Power Good output. Pulled Low if VFB is outside ±10% of 0.8 V V
ref
.
ABSOLUTE MAXIMUM RATINGS
Pin Name Symbol V
MAX
V
MIN
Main Supply Voltage Input VCC 15 V −0.3 V
Bootstrap Supply Voltage Input BOOT 35 V wrt/GND
40 V < 100 ns
15 V wrt/LX
−0.3 V
−0.3 V
−0.3 V
Switching Node (Bootstrap Supply Return) LX 35 V
40 V for < 100 ns
−5 V
−10 V for < 200 ns
High−Side Driver Output (Top Gate) UG 30 V wrt/GND
15 V wrt/LX
40 V for < 100 ns
−0.3 V wrt/LX
−5 V for < 200 ns
Low−Side Driver Output (Bottom Gate) LG 15 V −0.3 V
−5 V for < 200 ns
Feedback, VORPM FB, VORPM 6.0 V −0.3 V
COMP/DISB COMP/DISB 5.5 V −0.3 V
PGOOD PGOOD 7 V −0.3 V
MAXIMUM RATINGS
Rating Symbol Value Unit
Thermal Resistance, Junction−to−Ambient
R
q
JA
165 °C/W
Thermal Resistance, Junction−to−Case
R
q
JC
45 °C/W
Operating Junction Temperature Range T
J
0 to 150 °C
Operating Ambient Temperature Range T
A
0 to 95 °C
Storage Temperature Range T
stg
−55 to +150 °C
Moisture Sensitivity Level MSL 1 −
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
