|
|
PDF NCP81172 Data sheet ( Hoja de datos )
| Número de pieza | NCP81172 | |
| Descripción | 2-Phase Synchronous Buck Controller | |
| Fabricantes | ON Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de NCP81172 (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
NCP81172
2-Phase Synchronous Buck
Controller with Integrated
Gate Drivers and PWM VID
Interface
The NCP81172, a general−purpose two−phase synchronous buck
controller, integrates gate drivers and PWM VID interface in a
QFN−24 package and provides a compact−footprint power
management solution for new generation computing processors. It
receives power save command (PSI) from processors and operates in
1−phase diode emulation mode to obtain high efficiency in light−load
condition. Operating in high switching frequency up to 800 kHz
allows employing small size inductor and capacitors. The part is able
to support all−ceramic−capacitor applications.
Features
4.5 V to 24 V Input Voltage Range
Output Voltage up to 2.0 V with PWM VID Interface
Differential Output Voltage Sense
Integrated Gate Drivers
200 kHz ~ 800 kHz Switching Frequency
Power Saving Interface (PSI)
Power Good Output
Programmable Over Current Protection
Over Voltage Protection
Under Voltage Protection
Temperature Sense and Alert Output
Thermal Shutdown Protection
QFN−24, 4 x 4 mm, 0.5 mm Pitch Package
This is a Pb−Free Device
Typical Applications
GPU and CPU Power
Graphics Card Applications
Desktop and Notebook Applications
http://onsemi.com
1 24
QFN24
CASE 485L
MARKING DIAGRAM
81172
ALYWG
G
81172
A
L
Y
W
G
= Specific Device Code
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
PINOUT
18 17 16 15 14 13
19 PH2
20 LG2
21 PVCC
22 PGND
23 LG1
24 PH1
25
GND
COMP 12
FB 11
FBRTN 10
FS 9
VREF 8
REFIN 7
123456
(Top View)
ORDERING INFORMATION
Device
Package
Shipping†
NCP81172MNTXG QFN24
(Pb−Free)
4000 / Tape &
Reel
†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, 2013
April, 2013 − Rev. 1
1
Publication Order Number:
NCP81172/D
1 page  
NCP81172
PIN DESCRIPTION
Pin Name
1 BST1
2 HG1
3 EN
4 PSI
5 VID
6 VIDBUF
7 REFIN
8 VREF
9 FS
10 FBRTN
11 FB
12 COMP
13 TSNS
14 TALERT#
15 VCC
16 PGOOD
17 HG2
18 BST2
19 PH2
20 LG2
21 PVCC
22 PGND
23 LG1
24 PH1
25 THERM/GND
Type
Analog Power
Analog Output
Logic Input
Logic Input
Logic Input
Analog Output
Analog Input
Analog Output
Analog Input
Analog Input
Analog Input
Analog Output
Analog Input
Logic Output
Analog Power
Logic Output
Analog Output
Analog Power
Analog Input
Analog Output
Analog Power
Analog Ground
Analog Output
Analog Input
Analog Ground
Description
Bootstrap 1. Provides bootstrap voltage for the high−side gate drive of phase 1.
A 0.1 mF ~ 1 mF ceramic capacitor is required from this pin to PH1 (pin 24).
High−Side Gate 1. Directly connected with the gate of the high−side power MOSFET
of phase 1.
Enable. Logic high enables the device and logic low makes the device in standby
mode.
Power Saving Interface. Logic high enables 2 phase CCM operation, mid level
enables 1−phase CCM operation, and logic low enables 1−phase CCM/DCM
operation.
Voltage ID. Voltage ID input from processor.
Voltage ID Buffer. VID PWM pulse output from an internal buffer.
Reference Input. Reference voltage input for output voltage regulation. The pin is
connected to a non−inverting input of internal error amplifier.
Output Reference Voltage. Precise 2 V reference voltage output. A 10 nF ceramic
capacitor is required from this pin to GND.
Frequency Selection. A resistor from this pin to ground programs switching frequency.
Voltage Feedback Return Input. An inverting input of internal error amplifier.
Feedback. An inverting input of internal error amplifier.
Compensation. Output pin of error amplifier.
Temperature Sensing. Temperature sensing input.
Thermal Alert. Open drain output and active low indicates over temperature.
Voltage Supply of Controller. Power supply input pin of control circuits. A 1 mF or larger
ceramic capacitor bypasses this input to GND. This capacitor should be placed as
close as possible to this pin.
Power GOOD. Open−drain output. Provides a logic high valid power good output
signal, indicating the regulator’s output is in regulation window.
High−Side Gate 2. Connected with the gate of the high−side power MOSFET in
phase 2.
Bootstrap 2. Provides bootstrap voltage for the high−side gate drive of phase 2.
A 0.1 mF ~ 1 mF ceramic capacitor is required from this pin to PH2 (pin 19).
Phase Node 2. Connected to interconnection between high−side MOSFET and
low−side MOSFET in phase 2.
Low−Side Gate 2. Connected with the gate of the low−side power MOSFET in
phase 2.
Voltage Supply of Gate Drivers. Power supply input pin of internal gate drivers.
A 4.7 mF or larger ceramic capacitor bypasses this input to ground. This capacitor
should be placed as close as possible to this pin.
Power Ground. Power ground of internal gate drivers. Must be connected to the
system ground.
Low−Side Gate 1. Connected with the gate of the low−side power MOSFET in
phase 1.
A resistor may be applied between this pin and GND to program OCP threshold.
Phase Node 1. Connected to interconnection between high−side MOSFET and
low−side MOSFET in phase 1.
Thermal Pad and Analog Ground. Ground of internal control circuits. Must be
connected to the system ground.
http://onsemi.com
5
5 Page 
NCP81172
Figure 5. Switching Frequency Programmed by Resistor RFS at FS Pin
Soft Start
The NCP81172 has a soft start function. The output starts
to ramp up following a system reset period after the device
is enabled. The device is able to start up smoothly under an
output pre−biased condition without discharging the output
before ramping up.
REFIN Discharge
An internal switch in REFIN pin starts to short REFIN to
GND just after EN is pulled high and it turns off just before
the beginning of the soft start. The typical on resistance of
the switch is 6.25 W.
Output Discharge in Shut Down
The NCP81172 has an output discharge function when the
device is in shutdown mode. The resistors (2 kW per phase)
from PH node to PGND in both phases are active to
discharge the output capacitors.
Temperature Sense and Thermal Alert
The NCP81172 provides external temperature sense and
thermal alert in the normal operation mode, and disables the
function in the standby mode. The temperature sense and
thermal alert circuit diagram is shown in . An external
voltage divider, consisting of a NTC thermistor R_NTC and
a resistor R_TSNS, is employed to sense temperature and
program alert level. Usually the thermistor is placed close to
a hot spot like a power MOSFET. The NCP81172 monitors
the voltage at TSNS pin and compares the voltage to an
internal 1 V threshold by an internal comparator. Once the
TSNS voltage drops below 1 V, the comparator turns on an
open−drain switch at TALERT# pin and thus indicates a high
temperature alert. The thermal alert can be de−asserted when
TSNS voltage raises back to be higher than 1.05V. In an
exemplary application where a 100 kW (B = 4250 at 25C)
NTC thermistor is applied together with a 5.62 kW resistor,
an low−valid thermal alert signal is asserted when the
temperature of the NTC thermistor reaches 100C and
de−asserted when the temperature drops down to 97C.
Thermal Shutdown
The NCP81172 has a thermal shutdown protection to
protect the device from overheating when the die
temperature exceeds 150C. Once the thermal protection is
triggered, the fault state can be ended by re−applying VCC
and/or EN if the temperature drops down below 125C.
http://onsemi.com
11
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet NCP81172.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| NCP81172 | 2-Phase Synchronous Buck Controller | ON Semiconductor |
| NCP81174 | 4/3/2-Phase 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 |