|
|
PDF RT9259A Data sheet ( Hoja de datos )
| Número de pieza | RT9259A | |
| Descripción | 12V Synchronous Buck PWM DC-DC and Linear Power Controller | |
| Fabricantes | Richtek Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de RT9259A (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
RT9259A
12V Synchronous Buck PWM DC-DC and Linear Power
Controller
General Description
Features
The RT9259A is a dual-channel DC/DC controller
specifically designed to deliver high quality power where
12V power source is available. This part consists of a
synchronous buck controller and an LDO controller. The
synchronous buck controller integrates MOSFET drivers
that support 12V+12V bootstrapped voltage for high
efficiency power conversion. The bootstrap diode is built-
in to simplify the circuit design and minimize external part
count. The LDO controller drives an external N-MOSFET
for lower power requirement.
Other features include adjustable operation frequency,
internal soft start, under voltage protection, over current
protection and shut down function. With the above
functions, this part provides customers a compact, high
efficiency, well-protected and cost-effective solution. This
part comes to SOP-14 package.
Ordering Information
RT9259A
Package Type
S : SOP-14
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Note :
RichTek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
z Single 12V Bias Supply
z Support Dual Channel Power Conversion
`One Synchronous Rectified Buck PWM Controller
`One Linear Controller
z Both Controllers Drive Low Cost N-Channel
MOSFETs
z Adjustable Frequency from 150kHz to 1MHz
and Free-Run Frequency at 230kHz
z Small External Component Count
z Output Voltage Regulation
`PWM Controller : ±1% Accuracy
`LDO Controller : ±2% Accuracy
z Two Internal VREF Power Support Lower to 0.8V
z Adjustable External Compensation
z Linear Controller Drives N-Channel MOSFET Pass
Transistor
z Fully-Adjustable Outputs
z Under Voltage Protection for Both Outputs
z Adjustable Over Current Protection
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Graphic Card GPU, Memory Core Power
z Graphic Card Interface Power
z Motherboard, Desktop and Servers Chipset and Memory
Core Power
z IA Equipments
z Telecomm Equipments
z High Power DC-DC Regulators
Pin Configurations
(TOP VIEW)
www.DataSheet4U.com
BOOT
RT_DIS
COMP
FB
DRV
FBL
GND
2
3
4
5
6
7
14 UGATE
13 PHASE
12 PGND
11 LGATE
10 OCSET
9 VREF
8 VCC12
SOP-14
DS9259A-02 March 2007
www.richtek.com
1
1 page  
RT9259A
Absolute Maximum Ratings (Note 1)
z Supply Voltage, VCC -------------------------------------------------------------------------------------- 15V
z PHASE to GND
DC ------------------------------------------------------------------------------------------------------------- −5V to 15V
< 200ns ------------------------------------------------------------------------------------------------------ −10V to 30V
z BOOT to PHASE ------------------------------------------------------------------------------------------ 15V
z BOOT to GND
DC ------------------------------------------------------------------------------------------------------------- −0.3V to VCC+15V
< 200ns ------------------------------------------------------------------------------------------------------ −0.3V to 42V
z UGATE ------------------------------------------------------------------------------------------------------- VPHASE − 0.3V to VBOOT + 0.3V
z LGATE ------------------------------------------------------------------------------------------------------- GND − 0.3V to VCC + 0.3V
z DRV ---------------------------------------------------------------------------------------------------------- GND − 0.3V to VCC + 0.3V
z Input, Output or I/O Voltage ----------------------------------------------------------------------------- GND − 0.3V to 7V
z Power Dissipation, PD @ TA = 25°C
SOP-14 ------------------------------------------------------------------------------------------------------ 1.000W
z Package Thermal Resistance (Note 4)
SOP-14, θJA ------------------------------------------------------------------------------------------------- 100°C/W
z Junction Temperature ------------------------------------------------------------------------------------- 150°C
z Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------- 260°C
z Storage Temperature Range ---------------------------------------------------------------------------- −40°C to 150°C
z ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 3)
z Supply Voltage, VCC -------------------------------------------------------------------------------------- 12V ± 10%
z Junction Temperature Range ---------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range ---------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VCC = 12V, TA = 25°C unless otherwise specified)
Parameter
Symbol
Supply Input
Power Supply Voltage
VCC
Power On Reset
VVCCRTH
Power On Reset Hysteresis
VVCCHYS
Power Supply Current
IVCC
Oscillator
wwwF.DreaetaSRhuenetn4iUng.coFmrequency
Ramp Amplitude
fOSC
Test Conditions
VCC Rising
UGATE, LGATE Open
RRT = 110kΩ
Min Typ Max Units
-- 12 15 V
8.8 9.6 10.4 V
0.4 0.78 1.2
V
-- 3 -- mA
250 300 350 kHz
-- 1.6 --
V
To be continued
DS9259A-02 March 2007
www.richtek.com
5
5 Page 
RT9259A
If MOSFET with RDS(ON) = 16mΩ is used, the OCP
threshold current is about 25A. Once OCP is triggered,
the RT9259A enters hiccup mode and re-soft starts again.
The RT9259A shuts down after 4 time OCP hiccups.
Inductor Current
(20A/Div)
Time (2.5ms/Div)
Figure 6. Shorted then Start Up
IL
(20A/Div)
A well-designed compensator regulates the output voltage
to the reference voltage VREF with fast transient response
and good stability.
In order to achieve fast transient response and accurate
output regulation, an adequate compensator design is
necessary. The goal of the compensation network is to
provide adequate phase margin (greater than 45 degrees)
and the highest 0dB crossing frequency. It is also
recommended to manipulate loop frequency response that
its gain crosses over 0dB at a slope of −20dB/dec.
OSC
PWM
Comparator
ΔVOSC
-
+
Driver
VIN
Driver
L
PHASE
COUT
VOUT
ZFB
COMP
-
EA+
REF
ZIN
ESR
LGATE
(5V/Div)
UGATE
(5V/Div)
Time (5μs/Div)
Figure 7. Shorted then Start Up (Extended Figure 3)
Feedback Compensation
The RT9259A is a voltage mode controller. The control
loop is a single voltage feedback path including a
compensator and modulator as shown Figure 8. The
modulator consists of the PWM comparator and power
stage. The PWM comparator compares error amplifier EA
output (COMP) with oscillator (OSC) sawtooth wave to
provide a pulse-width modulated (PWM) with an amplitude
wwowf.VDIaNtaaSthteheet4PUH.cAomSE node. The PWM wave is smoothed
by the output filter LOUT and COUT. The output voltage (VOUT)
is sensed and fed to the inverting input of the error amplifier.
DS9259A-02 March 2007
C2 ZFB
C1 R2 C3
ZIN VOUT
R3
COMP
- FB
EA+
REF
R1
Figure 8. Closed Loop
1) Modulator Frequency Equations
The modulator transfer function is the small-signal transfer
function of VOUT/VCOMP (output voltage over the error
amplifier output. This transfer function is dominated by a
DC gain, a double pole, and a zero as shown in Figure 10.
The DC gain of the modulator is the input voltage (VIN)
divided by the peak to peak oscillator voltage VOSC. The
output LC filter introduces a double pole, 40dB/decade
gain slope above its corner resonant frequency, and a total
phase lag of 180 degrees. The resonant frequency of the
LC filter expressed as :
fLC =
1
2π LOUT × COUT
www.richtek.com
11
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet RT9259A.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| RT9259 | 12V Synchronous Buck PWM DC-DC and Linear Power Controller | Richtek Technology |
| RT9259A | 12V Synchronous Buck PWM DC-DC and Linear Power Controller | Richtek Technology |
| RT9259C | 12V Synchronous Buck PWM DC-DC and Linear Power Controller | Richtek Technology |
| 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 |