|
|
PDF NCV8853 Data sheet ( Hoja de datos )
| Número de pieza | NCV8853 | |
| Descripción | Automotive Grade Non-Synchronous Buck Controller | |
| Fabricantes | ON Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de NCV8853 (archivo pdf) en la parte inferior de esta página. Total 12 Páginas | ||
|
No Preview Available !
NCV8853
Automotive Grade
Non-Synchronous Buck
Controller
The NCV8853 is an adjustable−output non−synchronous buck
controller which drives an external P−channel MOSFET. The device
uses peak current mode control with internal slope compensation. The
IC incorporates an internal regulator that supplies charge to the gate
driver.
Protection features include internal soft−start, undervoltage lockout,
cycle−by−cycle current limit, hiccup−mode overcurrent protection,
hiccup−mode short−circuit protection.
Additional features include: power good signal, low quiescent
current sleep mode and externally synchronizable switching
frequency.
Features
• Ultra Low Iq Sleep Mode
• Adjustable Output with 800 mV ±2.0% Reference Voltage
• Wide Input of 3.1 to 44 V with Undervoltage Lockout (UVLO)
• Power Good (PG)
• Internal Soft−Start (SS)
• Fixed−Frequency Peak Current Mode Control
• Internal Slope Compensating Artificial Ramp
• Internal High−Side PMOS Gate Driver
• Regulated Gate Driver Current Source
• External Frequency Synchronization (SYNC)
• Programmable Cycle−by−Cycle Current Limit (CL)
• Hiccup Overcurrent Protection (OCP)
• Output Short Circuit Hiccup Protection (SCP)
• Space−Saving 8−PIN SOIC Package
• NCV Prefix for Automotive and Other Applications Requiring
Unique Site and Control Change Requirements; AEC−Q100
Qualified and PPAP Capable
• These Devices are Pb−Free and are RoHS Compliant
www.onsemi.com
8
1
SOIC−8
SUFFIX D
CASE 751
MARKING
DIAGRAM
8
V8853xx
ALYW
G
1
V8853xx = Specific Device Code
x = 00, 01
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package
PINOUT DIAGRAM
1 PG
2 EN/SYNC
3 COMP
4 FB
VIN 8
ISNS 7
GDRV 6
GND 5
ORDERING INFORMATION
Device
Package
Shipping†
NCV885300D1R2G SOIC−8 2500/Tape & Reel
(Pb−Free)
NCV885301DR2G SOIC−8 2500/Tape & Reel
(Pb−Free)
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
© Semiconductor Components Industries, LLC, 2015
August, 2015 − Rev. 4
1
Publication Order Number:
NCV8853/D
1 page  
NCV8853
ELECTRICAL CHARACTERISTICS (VIN = 3.4 V to 36 V, EN = 5 V. Min/Max values are valid for the temperature range
−40°C ≤ TJ ≤ 150°C unless noted otherwise, and are guaranteed by test, design or statistical correlation.)
Characteristic
Symbol
Conditions
Min Typ Max
Unit
CURRENT SENSE AMP
Input Bias Current
Isns,bias
NCV885300
NCV885301
30 50 mA
70 120
CURRENT LIMIT / OVER CURRENT PROTECTION
Cycle−by−Cycle Current
Limit Threshold
Vcl
85 100 115 mV
Cycle−by−Cycle Current
Limit Response Time
tcl
200 nsec
Over Current Protection
Threshold
Vocp
% of Vcl
125 150 175
%
Over Current Protection
Response Time
tocp
200 ns
GATE DRIVERS
Leading Edge Blanking
Time
ton,min
100 ns
Gate Driver Pull Up Current Isink VIN − VGDRV = 4 V
Gate Driver Pull Down
Current
Isrc VIN − VGDRV = 4 V
200 300 mA
200 300 mA
Gate Driver Clamp Voltage
(VIN – VGDRV)
Power Switch Gate to
Source Voltage
Vdrv
Vgs
VIN = 4 V
6.0 8.0 10
3.8
V
V
SHORT CIRCUIT PROTECTION
Startup Blanking Time
Short−Circuit Threshold
Voltage
tscp,dly
Vscp
From start of soft−start, % of soft−start time
% of Feedback Voltage (Vref)
105 300 %
65 70 75 %
Hiccup Time
SC Response Time
THERMAL SHUTDOWN
Thermal Shutdown
Threshold
thcp,dly
tscp
% of Soft−Start Time
Switcher Running
Tsd TJ rising
135
60 200
%
ns
160 170 180
°C
Thermal Shutdown
Hysteresis
Tsd,hys
TJ Shutdown – TJ Startup
10 15 20 °C
Thermal Shutdown Delay
ttsd TJ > Thermal Shutdown Threshold to stop
switching
200 ns
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
www.onsemi.com
5
5 Page 
NCV8853
The maximum reverse voltage the diode sees is the
maximum input voltage (with some margin in case of
ringing on the switch node). The maximum forward current
is the peak current limit of the NCV8853, or 150% of ICL.
(6) Output Inductor Selection
Both mechanical and electrical considerations influence
the selection of an output inductor. From a mechanical
perspective, smaller inductor values generally correspond to
smaller physical size. Since the inductor is often one of the
largest components in the power supply, a minimum
inductor value is particularly important in space−
constrained applications. From an electrical perspective, an
inductor is chosen for a set amount of current ripple and to
assure adequate transient response.
The output inductor controls the current ripple that occurs
over a switching period. A high current ripple will result in
excessive power loss and ripple current requirements. A low
current ripple will result in a poor control signal and a slow
current slew rate in the event of a load transient. A good
starting point for peak−to−peak ripple is around 10% of the
inductor current.To choose the inductor value based on the
peak−to−peak ripple current, use the following equation:
iL
+
VOUT @ (1 * DMIN)
L @ FSW
where:
iL: peak−to−peak output current ripple [Ap−p]
From this equation it is clear that the ripple current increases
as L decreases, emphasizing the trade−off between dynamic
response and ripple current. The peak and valley values of
the triangular current waveform are as follows:
IL(pk)
+
IOUT
)
iL
2
IL(vly)
+
IOUT
*
iL
2
where:
IL(pk): peak (maximum) value of ripple current [A]
IL(vly): valley (minimum) value of ripple current [A]
Saturation current is specified by inductor manufacturers as
the current at which the inductance value has dropped from
the nominal value, typically 10%. For stable operation, the
output inductor must be chosen so that the inductance is
close to the nominal value even at the peak output current,
IL(pk), it is recommended to choose an inductor with
saturation current sufficiently higher than the peak output
current, such that the inductance is very close to the nominal
value at the peak output current. This allows for a safety
factor and allows for more optimized compensation.
Inductor efficiency is another consideration when
selecting an output inductor. Inductor losses include dc and
ac winding losses, which are very low due to high core
resistance, and magnetic hysteresis losses, which increase
with peak−to−peak ripple current. Core losses also increase
as switching frequency increases.
Ac winding losses are based on the ac resistance of the
winding and the RMS ripple current through the inductor,
which is much lower than the dc current. The ac winding
losses are due to skin and proximity effects and are typically
much less than dc losses, but increase with frequency. Dc
winding losses account for a large percentage of output
inductor losses and are the dominant factor at switching
frequencies at or below 500 kHz. The dc winding losses in
the inductor can be calculated with the following equation:
PL(dc) + IOUT 2 @ Rdc
where:
PL(dc): dc winding losses in the output inductor
Rdc: dc resistance of the output inductor (DCR)
(7) Output Capacitor Selection
The output capacitor is a basic component for the fast
response of a power supply. In fact, for the first few
microseconds of a load transient, they supply the current to
the load. The controller recognizes the load transient and
proceeds to increase the duty cycle to its maximum.
Neglecting the effect of the ESL, the output voltage has a
first drop due to ESR of the bulk capacitor(s).
DVOUT(ESR) + DIOUT @ ESR
A lower ESR produces a lower ΔV during load transient.
In addition, a lower ESR produces a lower output voltage
ripple.
In the case of stepping into a short, the inductor current
approaches zero with the worst case initial current at the
current limit and the initial voltage at the output voltage set
point, calculating the voltage overshoot as follows:
ǸDVOS +
L
@ ICL
C
2
)
VOUT
2
*
V
OUT
Accordingly, a minimum amount of capacitance can be
chosen for maximum allowed output voltage overshoot:
ǒ ǓCMIN +
L @ ICL 2
2
VOUT ) DVOS(max) * VOUT 2
where:
CMIN: minimum amount of capacitance to minimize
voltage overshoot to ΔVOS(max) [F]
ΔVOS(max): maximum allowed voltage overshoot during
a short [V]
(8) Select Compensator Components
The Current Mode control method employed by the
NCV8853 allows the use of a simple, Type II compensation
to optimize the dynamic response according to system
requirements. Using a simulation tool such as CompCalc
can assist in the selection of these components.
www.onsemi.com
11
11 Page | ||
| Páginas | Total 12 Páginas | |
| PDF Descargar | [ Datasheet NCV8853.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| NCV8851 | Automotive Grade Synchronous Buck Controller | ON Semiconductor |
| NCV8851-1 | Automotive Grade Synchronous Buck Controller | ON Semiconductor |
| NCV8851B | Automotive Grade Synchronous Buck Controller | ON Semiconductor |
| NCV8852 | Automotive Grade Non-Synchronous Buck Controller | ON Semiconductor |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |