|
|
PDF IR3651SPBF Data sheet ( Hoja de datos )
| Número de pieza | IR3651SPBF | |
| Descripción | HIGH VOLTAGE SYNCHRONOUS PWM BUCK CONTROLLER | |
| Fabricantes | International Rectifier | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de IR3651SPBF (archivo pdf) en la parte inferior de esta página. Total 19 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
Data Sheet No.PD94720
IR3651SPbF
HIGH VOLTAGE SYNCHRONOUS PWM BUCK CONTROLLER
Features
• High Voltage Operating up to 75V
• Programmable Switching Frequency up to 400kHz
• 1A Output Drive Capability
• Precision Reference Voltage (1.25V)
• Programmable Soft-Start
• Programmable Over Current Protection
• Hiccup Current Limit Using MOSFET RDS(on)
sensing
• External Frequency Synchronization
• 14-pin SOIC Package
Applications
• 48V non-isolated DC to DC Converter
• Embedded Telecom Systems
• Networking and Computing Voltage Regulator
• Distributed Point of Load Power Architectures
• General high voltage DC/DC Converters
Description
The IR3651 is a high voltage PWM controller
designed for high performance synchronous Buck
DC/DC applications. The IR3651 drives a pair of
external N-MOSFETs using a programmable
switching frequency up to 400kHz allows flexibility
to tune the operation of the IC to meet system
level requirements, and synchronization allows
the simplification of system level filter design. The
output voltage can be precisely regulated using
the internal 1.25V reference voltage for low
voltage applications. Protection such as under
voltage lockout and hiccup current limit are
provided to give required system level security in
the event of fault conditions.
Vaux=12V
Vin: 12V-75V
C2
R5
C6
10/11/2006
C3
DRVcc
Vcc
Vb
HDrv
SYNC
Vs
Rt IR3651S
OCset
SS/SD
LDrv
PGnd
Gnd Comp Fb
C1
C4
Q1
ROCset
Q2
C7 R4
L1
C8
Vout
C5 R1 R3
C9
R2
C10
Typical application Circuit
ORDERING INFORMATION
PKG PACKAGE
DESIG DESCRIPTION
S IR3651SPBF
S IR3651STRPBF
PIN
COUNT
14
14
PARTS
PER TUBE
55
--------
PARTS
PER REEL
-------
2500
T&R
ORIANTAION
Fig A
1 page  
IR3651SPbF
Recommended Operating Conditions
Symbol Definition
Min Max Units
Vbus Converting Voltage
12 75 V
Vcc Supply Voltage
4.5 13.2
V
DRVcc
Supply Voltage
10 16 V
Vb to Vs
Supply Voltage
10 16 V
Fs Operating Frequency 100 400 kHz
Tj
Junction Temperature
-40
125
oC
Electrical Specifications
Unless otherwise specified, these specifications apply over Vcc=5V; DRVcc=Vb=12V, 0oC<Tj< 125oC
Parameter
SYM
Test Condition
Min TYP MAX Unit
s
Reference Voltage
Feedback Voltage
Accuracy
VFB
0oC<Tj<125oC
-40oC<Tj<125oC, Note1
1.25
-1.5
-3
+1.5
+1.5
V
%
%
Fb Voltage Line Regulation
LREG
5V<Vcc<12V
2.0 mV
Supply Current
VCC Supply Current (Stat)
VCC Supply Current (Dyn)
DRVcc Supply Current (Stat)
ICC(Static)
ICC(Dynamic)
IC(Static)
DRVcc Supply Current (Dyn)
IC(Dynamic)
Vb Supply Current (Stat)
Vb Supply Current (Dyn)
Ib(Static)
Ib(Dynamic)
Under Voltage Lockout
VCC-Start-Threshold
VCC-Stop-Threshold
VCC-Hysteresis
DRVcc-Start-Threshold
DRVcc-Stop-Threshold
DRVCc-Hysteresis
Vb-Start-Threshold
Vb-Stop-Threshold
Vb-Hysteresis
VCC_UVLO(R)
VCC_UVLO(F)
DRcc_UVLO(R)
DRVcc_UVLO(F)
Vb_UVLO(R)
Vb_UVLO(F)
Oscillator
Frequency
FS
Ramp Amplitude
Min Duty Cycle
Min Pulse Width
Max Duty Cycle
Vramp
Dmin
Dmin(ctrl)
Dmax
Sync Frequency Range
Sync Pulse Duratin
Sync high Level Threshold
Sync Low Level Threshold
Sync(Fs)
Sync(puls)
Sync(H)
Sync(L)
SS=0V, No Switching
Fs=200kHz, CLOAD=1.5nF
SS=0V, No Switching
Fs=200kHz, CLOAD=1.5nF
SS=0V, No Switching
Fs=200kHz, CLOAD=1.5nF
Supply ramping up
Supply ramping down
Supply ramping up and down
Supply ramping up
Supply ramping down
Supply ramping up and down
Supply ramping up
Supply ramping down
Supply ramping up and down
Rt=120K
Rt=51K
Note2
Fb=2V
Fs=200kHz, Note2
Fs=200kHz, Fb=1.2V
Fs=400kHz, Fb=1.2V
20% above free running freq
4.0
3.75
0.15
8.3
7.5
0.6
8.3
7.5
0.6
170
340
80
70
200
2
6
6
0.3
4
0.3
4.5
4.17
0.25
9
8.2
9
8.2
200
400
1.25
7
7
0.5
5
0.5
5.5
4.35
4.1
0.3
9.7
8.9
0.9
9.7
8.9
0.9
230
460
0
200
480
0.8
mA
mA
mA
mA
mA
mA
V
V
V
V
V
V
V
V
V
kHz
V
%
ns
%
kHz
ns
V
V
10/11/2006
5
5 Page 
Over-Current Protection
The over current protection is performed by
sensing current through the RDS(on) of low side
MOSFET. This method enhances the converter’s
efficiency and reduce cost by eliminating a
current sense resistor. As shown in figure 6, an
external resistor (RSET) is connected between
OCSet pin and the drain of low side MOSFET
(Q2) which sets the current limit set point.
The internal current source develops a voltage
across RSET. When the low side MOSFET is
turned on, the inductor current flows through the
Q2 and results a voltage which is given by:
VOCSet = (IOCSet ∗ R )OCSet − (RDS(on) ∗ IL )
--(2 )
IOCSET
IR3651
Hiccup
Control
Q1
OCSet RSET
L1 VOUT
Q2
IR3651SPbF
20uA
28uA
SS1 / SD 20
3uA
OCP
Fig. 7: 3uA current source for discharging
soft-start capacitor during hiccup
The OCP circuit starts sampling current
approximately 200ns before the low gate drive
turns off. The OCSet pin is internally clamped
during deadtime to prevent false trigging, figure 8
shows the OCSet pin during one switching cycle.
Fig. 6: Connection of over current sensing resistor
The critical inductor current can be calculated by
setting:
VOCSet = (IOCSet ∗ ROCSet) − (RDS(on) ∗ IL ) = 0
I = I = R R ∗ ISET L(critical)
OCSet OCSet
DS(on)
--(3 )
ISET
= IL(critical)
= 1.5
* Io
+
∆iL
2
An over current is detected if the OCSet pin goes
below ground. This trips the OCP comparator
and cycles the soft start function in hiccup mode.
The hiccup is performed by charging and
discharging the soft-start capacitor in certain
slope rate. As shown in figure 7 a 3uA current
source is used to discharge the soft-start
capacitor.
The OCP comparator resets after every soft start
cycles, the converter stays in this mode until the
overload or short circuit is removed. The
converter will automatically recover.
Fig. 8: OCset pin during normal condition
Ch1: Inductor point, Ch2:Ldrv, Ch3:OCSet
The value of RSET should be checked in an actual
circuit to ensure that the over current protection
circuit activates as expected. The IR3651 current
limit is designed primarily as disaster preventing,
"no blow up" circuit, and doesn't operate as a
precision current regulator.
10/11/2006
11
11 Page | ||
| Páginas | Total 19 Páginas | |
| PDF Descargar | [ Datasheet IR3651SPBF.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| IR3651SPBF | HIGH VOLTAGE SYNCHRONOUS PWM BUCK CONTROLLER | International Rectifier |
| 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 |