Richtek RT8005PQV Schematic [ru]

RT8005

1A, 2MHz, High-Efficiency Synchronous Buck PWM Converter

General Description

The RT8005 is a high-efficiency synchronous buck PWM

converter with integrated P-Channel and N-Channel power

MOSFET switches. Capable of delivering 1A output current

over a wide input voltage range of 2.4V to 5.5V, the RT8005

is ideally suited for portable applications powered by a

single Li-Ion battery or by 3-cell NiMH/NiCd batteries. The

device operates at 2MHz PWM switching fixed frequency,

can use smaller CIN, C

The RT8005 integrates two low R

capacitor and inductor.

OUT

230mΩ and 180mΩ

DS(ON)

of high and low side switching MOSFETs to reduce board

space, as only resistors and capacitors along with one

inductor are required externally for operation. The RT8005

has adjustable output range down to 0.5V. The other

features include internal soft-start, chip enable, over

temperature and over current protections. It is available in

a space-saving VDFN-10L 3x3 package.

Ordering Information

RT8005

Package Type
QV : VDFN-10L 3x3 (V-Type)

Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)

Note :

Richtek 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.

Features

l 2.4V to 5.5V Input Voltage Range
l Adjustable Output from 0.5V to V
l Guaranteed 1A Output Current
l Accurate Reference : 0.5V (± 1.5%)
l Up to 90% Conversion Efficiency
l Typical Quiescent Current : 200µA
l Integrated Low R

High and Low Side Power

DS(ON)

IN

MOSFET Switches : 230mΩ and 180mΩ

l Current Mode PWM Operation
l Fixed Frequency : 2MHz
l 100% Maximum Duty Cycle for Lowest Dropout
l Internal Soft-Start
l No Schottky Diode Required
l Over Temperature and Over Current Protection
l Small 10-Lead VDFN 3x3 Package
l RoHS Compliant and 100% Lead (Pb)-Free

Applications

l Battery-Powered Equipments

l Low Power CPU and DSP Supplies

l Digital Cameras and Hard Disks

l Protable Instruments and Notebook Computers

l Celluar Phones, PDAs, and Handheld PCs

l USB-Based DSL Modems and Other Network Interface

Cards

Pin Configurations

(TOP VIEW)

PGND

10

9

PGND

8

GND

7

COMP

9

11

FB

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

1

LX

2

PVDD

3

PVDD

4

VDD

5

EN

VDFN-10L 3x3

GND

area.

DS8005-10 March 2011 www.richtek.com

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RT8005

Typical Application Circuit

V

2.4V to 5.5V

Recommended component selection for Typical Application Circuit.

V

OUT

(V)

VIN (V) CIN (uF) C

0.5 2.4 to 5.5

IN

2,3

PVDD

PGND

OUT

2.2µH

1

LX

6

FBCOMP

9, 10

(uH) R1 (kΩ) R2 (kΩ) C

Chip Enable

C

2.2µF

C

COMP

10nF

OUT

IN

5

EN

7

GND

(uF) L

4

VDD

RT8005

8,
11 (Exposed Pad)

2.2 2.2/4.7 2.2 10 Open 10

L

OUT

R1
10k

R2

7.15k

V

1.2V/1A

C

OUT

2.2µF

OUT

COMP

(nF)

1 2.4 to 5.5

1.2 2.4 to 5.5

1.8 2.4 to 5.5

2.5 3.3 to 5.5

3.3 4.2 to 5.5

2.2 2.2/4.7 2.2 10 10 10

2.2 2.2/4.7 2.2 10 7.15 10

2.2 2.2/4.7 2.2 10 3.83 10

2.2 2.2/4.7 2.2 10 2.49 10

2.2 2.2/4.7 2.2 10 1.78 10

Suggested Inductors

Component

Supplier

Series Inductance

(µH)

DCR

(mΩ)

Current Rating

(mA)

Dimensions

(mm)

ABC SR0403 2.2 47 2600 4.5x4x3.2

Sumida CDRH3D16

2.2 59 1750 4x4x1.8

GOTREND GTSD53 2.2 29 2410 5x5x2.8

Suggested Capacitors For CIN and C
Component Supplier

Part No. Capacitance (uF) Case Size

OUT

TDK C1608X5R1A225M 2.2 0603

Panasonic ECJ1VB0J225M 2.2 0603

TAIYO YUDEN JMK107BJ225M 2.2 0603

DS8005-10 March 2011www.richtek.com

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Functional Pin Description

ormally VDD is

Floating this pin is

Switcher Feedback Voltage. This pin is the inverting input of the error amplifier.

h an external resistor divider network. FB

Compensation Input. This pin is the output of the internal error amplifier. Connect

signal components, compensation components and the

exposed pad on the bottom side of the IC should connect to this ground, which in

The exposed pad must be soldered to a

Pin No. Pin Name

1 LX Internal Power MOSFET Switches Output. Connect this pin to the inductor.

2, 3 PVDD Power Input Supply. Decouple this pin to PGND with a capacitor.

4 VDD

5 EN

Signal Input Supply. Decouple this pin to GND with a capacitor. N
equal to PVDD.

Chip Enable (Active High). Logic low shuts down the converter.
forbidden.

RT8005

Pin Function

6 FB

FB senses the switcher output throug
regulation voltage is 0.5V.

7 COMP

an external capacitor to compensate the regulator controlled loop.

Signal Ground. All small-

8,

Exposed Pad (11)

GND

turn connects to PGND at one point.
large PCB and connected to GND for maximum power dissipation.

9, 10 PGND Power Ground. Connect this pin close to the terminal of CIN and C

Function Block Diagram

EN

Slope

Compensation

+

Error

Amplifier

-

COMP

FB

Shutdown

Control

Oscillator

V

REF

Current Limit

Detector

-

PWM

Comparator

+

VDD

Over

Temperature

Detector

Control

Logic

Zero

Detector

Current

Sense

Driver

PVDD

OUT

.

LX

GND

DS8005-10 March 2011 www.richtek.com

PGND

3

RT8005

Absolute Maximum Ratings (Note 1)

l Supply Voltage, PVDD and VDD ------------------------------------------------------------------------------−0.3V to 6V
l EN, FB Voltage---------------------------------------------------------------------------------------------------−0.3V to V
l PGND to GND----------------------------------------------------------------------------------------------------−0.3V to 0.3V
l LX Voltage---------------------------------------------------------------------------------------------------------−0.3V to (V

l Power Dissipation, P

@ T

D

= 25°C

A

VDFN-10L 3x3----------------------------------------------------------------------------------------------------1.923W

l Package Thermal Resistance (Note 2)

VDFN-10L 3x3, θJA-----------------------------------------------------------------------------------------------52°C/W

l Junction Temperature-------------------------------------------------------------------------------------------150°C
l Lead Temperature (Soldering, 10 sec.)----------------------------------------------------------------------260°C
l Storage Temperature Range----------------------------------------------------------------------------------- −65°C to 150°C

l ESD Susceptibility (Note 3)

HBM (Human Body Mode)-------------------------------------------------------------------------------------2kV

MM (Machine Mode)--------------------------------------------------------------------------------------------200V

Recommended Operating Conditions (Note 4)

l Supply Voltage, PVDD and VDD------------------------------------------------------------------------------2.4V to 5.5V

l Enable Input Voltage,

l Ambient Temperature Range----------------------------------------------------------------------------------−40°C to 85°C
l Junction Temperature Range----------------------------------------------------------------------------------−40°C to 125°C

-------------------------------------------------------------------------------------0V to V

VEN

DD

DD

DD

+ 0.3V)

Electrical Characteristics

(V

= 3.3V, T

DD

Supply Current

Quiescent Current

Shutdown Current

Reference

Reference Voltage

Oscillator

Switching Frequency Range

Maximum Duty Cycle DC

Output Voltage

Line Regulation

Load Regulation

Power Switches

R

DS(ON)

R

DS(ON)

Current Limit

= 25°C, unless otherwise specified)

A

Parameter Symbol

IQ

I

SHDN

V

f

OSC

of P-MOSFET R

of N-MOSFET R

I

LIMIT

REF

P_FET

N_FET

V

Test Conditions Min Typ Max Unit

V

V

EN

I

OUT

EN

= 3.3V, V

= 0mA

= 0V

FB

= V

+ 0.15V,

REF

-- 200 400 µA

-- 0.01

0.4925 0.5 0.5075 V

1.7 2.0 2.3 MHz

V

PVDD

V

DD

10mA < I

V

PVDD

V

PVDD

PVDD

= V

= 2.4V to 5.5V, I

OUT

LOAD

LOAD

< 600mA

= 3.3V, ILX = 300mA

= 3.3V, I

= 3.3V, V

= −300mA

LX

= V

FB

= 100mA

- 0.15V

REF

100

-- -- +1.5 %

-- -- +1.5 %

-- 230 -- mΩ

-- 180 --

-- 1.8 -- A

-- -- %

1 µA

mΩ

To be continued

DS8005-10 March 2011www.richtek.com

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