Document
NCV8881
Buck Regulator Automotive, Watchdog
1.5 A
The NCV8881 consists of a Buck switching regulator (SMPS) with a combination SMPS output undervoltage monitor and CPU watchdog circuit. In addition, two fixed−voltage low dropout regulator outputs are provided, and share an LDO output voltage status output. Once enabled, regulator operation continues until the Watchdog signal is no longer present. The NCV8881 is intended for Automotive, battery−connected applications that must withstand a 40 V load dump. The switching regulator is capable of converting the typical 9 V to 19 V automotive input voltage range to outputs from 3.3 V to 8 V at a constant switching frequency, which can be resistor programmed or synchronized to an external clock signal. Enable input threshold and hysteresis are programmable, with the enable input state replicated at an open drain Ignition Buffer output. The regulators are protected by current limiting, input overvoltage and overtemperature shutdown, as well as SMPS short circuit shutdown.
Features
• 1.5 A Switching Regulator (internal power switch) • 100 mA, 5 V LDO Output • 40 mA, 8.5 V LDO Output • Operating Range 5 V to 19 V • Programmable SMPS Frequency • SMPS can be Synchronized to an External Clock • Programmable SMPS Output Voltage Down to 0.8 V • $2% Reference Voltage Tolerance • Internal SMPS Soft−Start • Voltage−mode SMPS Control • SMPS Cycle−by−Cycle Current Limit and Short−Circuit Protection • Internal Bootstrap Diode • Logic level Enable Input • Enable Input Hysteresis Programmable by External Resistor Divider • Enable Input State is Replicated at an Open Drain Output • CPU Watchdog with Resistor Programmable Delays • Watchdog Reset Output also Indicates SMPS Output Out of Regulation • Battery Input Withstands Load Dump to 40 V • Low Standby Current • Thermal Shutdown (TSD) • NCV Prefix for Automotive and Other Applications Requiring Site
and Change Controls
• These are Pb−Free Devices
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MARKING DIAGRAMS
16
16 1
SO−16W EP PW SUFFIX CASE 751AG
NCV8881 AWLYYWWG
1
A
= Assembly Location
WL
= Wafer Lot
YY
= Year
WW = Work Week
G
= Pb−Free Package
(Note: Microdot may be in either location)
PIN CONNECTIONS
1 IGNBUF
WDI RDLY RESB
EN SYNC ROSC
GND
16 5P0 LDOMON 8P5 VIN SW BST FB COMP
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package dimensions section on page 32 of this data sheet.
Applications
• Audio • Infotainment
• Safety – Vision Systems • Instrumentation
© Semiconductor Components Industries, LLC, 2011
1
September, 2019 − Rev. 1
Publication Order Number: NCV8881/D
NCV8881
IGNITION BUFFER
RIGBUF
IGNBUF
FROM CPU WATCHDOG OUT
WDI
5P0 LDOMON
RMON
REGULATED 5.0V
CS5P0
LDO MONITOR
RDLY
RDLY
TO CPU RESET
RRESB
RESB
ENABLE R1 R2
SYNC
EN SYNC
ROSC
ROSC
GND
8P5
BEAD C8P5
REGULATED 8.5V
CS8P5
VIN CIN
BATTERY
SW BST
CBST
REGULATED SMPS OUTPUT
L1
DFW CZ1
COUT
RP2
RFB1
FB COMP
CP1
RZ1
CP3
RFB2
Figure 1. Typical Application
IGNITION BUFFER
RIGBUF
IGNBUF 1
BUFFERED ENABLE
WATCHDOG INPUT
WDI 2
RDLY 3
RDLY
CPU RESET
RRESB RESB 4
QIB
WATCHDOG TIMER
ENABLE
R1 R2
QRB EN
5
CLAMP
RH
QH
SYNC ROSC
SYNC 6
ROSC 7
GND 8
OSCILLATOR
LOGIC
NOPULSE
TSD
FAULT(H)
VIN_OV /UVLO
ENABLE HYSTERESIS
TEMP SENSE
DBST2 5V REGULATOR
QLM MONITOR
DBST1 8.5V
REGULATOR
POWER SWITCH
5P0 16
LDOMON 15
RMON CS5
S+5
LDO MONITOR
8P5 14
C8P5
BEAD CS8P5
S+8.5
VIN 13
BATTERY
CIN
SW
12 CBST
L1
BST 11
DFW
SWITCHER OUT
COUT
SW_UV
OC RUN
PWM COMPARATOR
NCV8881
UNDERVOLTAGE MONITOR
SHORT CKT MONITOR
ERROR AMP
FB 10 REF
CP1 RZ1
COMP 9
CZ1 RP2
CP3
RFB1 RFB2
Figure 2. NCV8881 Detailed Block Diagram
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NCV8881
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Min/Max Voltage on WDI
−0.3 to 7
V
Min/Max Voltage on RDLY
−0.3 to 7
V
Min/Max Voltage on RESB
−0.3 to 7
V
Min/Max Voltage on EN
−0.3 to 10
V
Max EN Current
10
mA
Min EN Current (with zero VIN voltage)
−10
mA
Min/Max Voltage on SYNC
−0.3 to 7
V
Min/Max Voltage on ROSC
−0.3 to 7
V
Min/Max Voltage COMP
−0.3 to 7
V
Min/Max Voltage FB
−0.3 to 7
V
Min Voltage SW
– DC − 20 ns
−0.7
V
−3
Max Voltage VIN to SW
40
V
Max Voltage VIN
40
V
Min/Max Voltage BST
−0.3 to 30
V
Min/Max Voltage BST to SW
−0.3 to 15
V
Min/Max Voltage on 8P5
−0.3 to 9.5
V
Max 8P5 Current
70
mA
Min/Max Voltage on LDOMON
−0.3 to 7
V
Min/Max Voltage on 5P0
−0.3 to 7
V
Min/Max Voltage IGNBUF
−0.3 to 7
V
Storage Temperature range
−55 to +150
°C
Operating Junction Temperature Range
TJ
−40 to + 150
°C
ESD withstand Voltage Human Body Model
VESD
2.0
kV
Machine Model
200
V
Charged Device Model
>1.0
kV
Moisture Sensitivity
MSL
Level 1
Peak Reflow Soldering Temperature
260
°C
Stresses exceeding Maximum Ratings may damage the device. Maximum Rati.