rt9202b Richtek Technology Corporation, rt9202b Datasheet

no-image

rt9202b

Manufacturer Part Number
rt9202b
Description
Single Synchronous Buck Dc-dc Controller
Manufacturer
Richtek Technology Corporation
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
RT9202B
Manufacturer:
RICHTEK/立锜
Quantity:
20 000
Company:
Part Number:
rt9202bPS
Quantity:
90
Single Synchronous Buck PWM DC-DC Controller
General Description
The RT9202B is a single power supply PWM DC-DC
converter controller designed to drive N-MOSFET in a
synchronous buck topology. The IC integrates the control,
output adjustment, monitoring and protection functions in
a small 8-pin package.
The RT9202B uses a low gain voltage mode PWM control
for simple application design. An internal 0.8V reference
allows the output voltage to be precisely regulated to
low voltage requirement. A fixed 300kHz oscillator
reduces the component size for saving board space.
The RT9202B features over current protection, over voltage
protection, and under voltage lock-out. The output current
is monitored by sensing the voltage drop across the
MOSFET's R
sensing resistor.
Ordering Information
Note :
RichTek Pb-free and Green products are :
DS9202B-03 March 2007
RT9202B
}RoHS compliant and compatible with the current require-
}Suitable for use in SnPb or Pb-free soldering processes.
}100% matte tin (Sn) plating.
ments of IPC/JEDEC J-STD-020.
DS(ON)
Package Type
S : SOP-8
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
, which eliminates the need for a current
cial Standard)
Features
l
l
l
l
l
l
l
l
l
l
l
l
Applications
l
l
l
l
l
l
l
l
l
Pin Configurations
Operate From 5V
0.8V Internal Reference
Drive Two N-MOSFETs
Voltage Mode PWM Control
Fast Transient Response
Fixed 300kHz Oscillator Frequency
Full 0 to 100% Duty Cycle
Internal Soft Start
Adaptive Non-Overlapping Gate Driver
Over-Current Monitor Uses MOSFET R
Over-Voltage Protection Uses Low-Side MOSFET
RoHS Compliant and 100% Lead (Pb)-Free
Motherboard Power Regulation for Computers
Subsystems Power Supplies
Cable Modems, Set Top Box, and DSL Modems
DSP and Core Communications processor Supplies
Memory Power Supplies
Personal Computer Peripherals
Industrial Power Supplies
5V-Input DC-DC Regulators
Low Voltage Distributed Power Supplies
UGATE
LGATE
BOOT
GND
(TOP VIEW)
2
3
4
SOP-8
8
7
6
5
RT9202B
PHASE
OCSET
FB
VCC
www.richtek.com
DS(ON)
1

Related parts for rt9202b

rt9202b Summary of contents

Page 1

... The IC integrates the control, output adjustment, monitoring and protection functions in a small 8-pin package. The RT9202B uses a low gain voltage mode PWM control for simple application design. An internal 0.8V reference allows the output voltage to be precisely regulated to low voltage requirement. A fixed 300kHz oscillator reduces the component size for saving board space ...

Page 2

... PHASE BOOT 7 2 OCSET UGATE V OUT 2. GND VCC LGATE RT9202B C4 1uF R3 R2 120 250 C6 10nF Figure 2. RT9202B powered from 12V and 5V D1 MA732 5uH 1uF C3 1000uF 1uF 5uH 1uF C3 1000uF ML DS9202B-03 March 2007 5V C1 470uF ...

Page 3

... C BOOT BOOT 0.1uF RT9202B Layout Placement Layout Notes 1. Put CIN1 & CIN2 to be near the MU drain and ML source nodes. 2. Put RT9202B to be near the C 3. Put C as close as to BOOT pin BOOT 4. Put C as close as to VCC pin VCC Power on Reset ...

Page 4

... This pin provides the gate drive for the lower MOSFET. VCC (Pin 5) This is the main bias supply for the RT9202B. This pin also provides the gate bias charge for the lower MOSFET gate. The voltage at this pin is monitored for power-on reset (POR) purpose ...

Page 5

... CC BOOT V = 4.5V OCSET V = 4.5V OCSET V OSC BOOT= 12V R UGATE BOOT UGATE UGATE UGATE 1V, LGATE CC LGATE LGATE LGATE RT9202B +150 +125 C Min Typ Max Units -- 3.85 4.1 4.35 V 0.3 0.5 0.7 V 0.8 1.25 2.0 V 0.784 0.8 0.816 V 250 300 350 kHz -- 1 ...

Page 6

... RT9202B Parameter Protection FB Over-Voltage Trip FB Under-Voltage Trip OCSET Current Source Soft-Start Interval Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied ...

Page 7

... Time (2.5ms/Div) Load Transient UGATE V OUT Time (5us/Div) DS9202B-03 March 2007 LGATE OUT 2.2V OUT C = 3000uF OUT RT9202B Dead Time V CC UGATE LGATE Time (50ns/Div) Power Off 2.2V OUT OUT Time (50ms/Div) Load Transient UGATE ...

Page 8

... RT9202B Bootstrap Wave Form UGATE LGATE PHASE Time (1us/Div) Reference vs. Temperature 0.803 0.802 0.801 0.800 0.799 0.798 0.797 0.796 -50 0 Temperature POR (Rising/Falling) vs. Temperature 4.3 Rising 4.2 4.1 4.0 3.9 3.8 Falling 3.7 3.6 -50 0 Temperature www.richtek.com 5V 2.2V CC OUT 50 100 150 ( C) 50 100 150 ( C) Short Circuit Hiccup V CC ...

Page 9

... LGATE RT9202B Figure 1. Single 5V power Supply Operation Dual Power Operation The RT9202B is designed to regulate a 6.0V at VCC pin automatically when BOOT pin is powered by 12V system with ATX 5V/12V power supply, the RT9202B is ideal for higher current application due to the higher gate ...

Page 10

... IN tracking the OCSET DS(ON) DS(ON) OCSET Shutdown Pulling low the OCSET pin can shutdown the RT9202B PWM controller as shown in typical application circuit I)/2 Inductor Selection The RT9202B was designed for V application mainly. Figure 5 shows the typical topology and waveforms of step-down converter. The ripple current of inductor can be calculated as follows: ...

Page 11

... The output amplitude of ramp oscillator is 1.75V, the loop gain and loop pole/zero are calculated as follows : DC loop gain filter pole P Error Amp pole P ESR zero The RT9202B Bode plot as shown Figure 6 is stable in most of application conditions. RT9202B 1. 93mV 37mV 58mV 23mV ...

Page 12

... Figure 8 www.richtek.com 12 Feedback Divider The reference of RT9202B is 0.8V. The output voltage can be set using a resistor based divider as shown in Figure 9. Put the R1 and R2 as close as possible to FB pin and R2 should less than avoid noise coupling. The C1 capacitor is a speed-up capacitor for reducing output ripple to meet with the requirement of fast transient load ...

Page 13

... There are two sets of critical components in a DC-DC converter using the RT9202B. The switching power components are most critical because they switch large amounts of energy, and as such, they tend to generate equally large amounts of noise. The critical small signal components are those connected to sensitive nodes or those supplying critical bypass current ...

Page 14

... RT9202B Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 www.richtek.com Dimensions In Millimeters Min Max 4.801 5.004 3.810 3.988 1.346 1.753 0.330 0.508 1.194 1 ...

Related keywords