TS2509 [TSC]

3A / 500KHz PWM Buck Converter; 3A / 500KHz的PWM降压转换器


型号：	TS2509
厂家：	TAIWAN SEMICONDUCTOR COMPANY, LTD
描述：	3A / 500KHz PWM Buck Converter 3A / 500KHz的PWM降压转换器转换器
文件：	总9页 (文件大小：492K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

TS2509

3A / 500KHz PWM Buck Converter

SOP-8

Pin Definition:

1. FB

8. Vss

2. EN

3. Comp

4. Vcc

7. Vss

6. SW

5. SW

General Description

TS2509 consists of step-down switching regulator with PWM control. These devise include a reference voltage

source, oscillation circuit, error amplifier, internal PMOS and etc. TS2509 provides low-ripple power, high efficiency,

and excellent transient characteristics. The PWM control circuit is able to the duty ratio linearly form 0 up to 100%.

This converter also contains an error amplifier circuit as well as a soft-start circuit that prevents overshoot at startup.

An enable function, an over current protect function and short circuit protect function are built inside, and when OCP

or SCP happens, the operation frequency will be reduced. Also, an internal compensation block is built in to minimum

external component count. With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode

connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply

units for portable devices when coupled with the SOP-8L package, providing such outstanding features as low current

consumption. Since this converter can accommodate an input voltage up to 23V, it is also suitable for the operation

via an AC adapter.

Features

Ordering Information

●

Input Voltage: 3.6V~23V

Part No.

Package

SOP-8

Packing

Output Voltage: 0.8V~Vcc

Duty Ratio: 0%~100% PWM Control

Oscillation Frequency: 500kHz typ.

Soft-Start (SS), Current Limit (CL), Enable Function

Thermal Shutdown Function

TS2509CS RL

2.5Kpcs / 13” Reel

Application

●

Simple High-efficiency Step down Regulator

On-Card Switching Regulators

Short Circuit Protect (SCP)

●

External SW P-Channel MOSFET

Low ESR output capacitor (MLCC application)

Absolute Maximum Rating

Parameter

Symbol

V_CC

V_FB

Rating

V_SS- 0.3 to V_SS+ 25

V_SS- 0.3 to V_CC

V_SS- 0.3 to V_CC+ 0.3

Internally limited

-40 to +150

Unit

VCC Pin Voltage

Feedback Pin Voltage

ON/OFF Pin Voltage

V_EN

Switch Pin Voltage

V_SW

P_D

Power Dissipation

℃

Storage Temperature Range

Operating Temperature Range

Operating Supply Voltage

Thermal Resistance from Junction to case

Thermal Resistance from Junction to ambient

T_{ST G}

T_OP

-20 to +125

℃

V_OP

θ_JC

+3.6 to +23

℃/W

θ_JA

1/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Electrical Specifications (V_IN=12V, Ta=25^oC unless otherwise noted)

Characteristics

Symbol

Conditions

I_OUT=0.1A

Min

Typ

Max

Units

Feedback Voltage

Quiescent Current

Feedback Bias Current

Shutdown Supply Current

Current limit

0.784

0.800

0.816

V_FB

V_FB=1.2V force driver off

I_OUT=0.1A

I_q

0.1

0.5

I_FB

I_SD

V_EN=0V

I_SW

Line Regulation

V_CC= 5V~23V, I_OUT=0.2A

I_OUT= 0.1 to 3A

0.6

0.2

500

1.2

0.4

600

∆V_OUT/V_OUT

F_OSC

V_SH

Load Regulation

Oscillation Frequency

SW pin

400

2.0

KHz

High (regulator ON)

Low (regulator OFF)

V_EN=2.5V (ON)

EN Pin Logic input

threshold voltage

0.8

V_SL

-10

I_SH

EN Pin Input Current

Soft-Start Time

V_EN=0.3V (OFF)

I_SL

T_SS

0.3

V_CC= 5V, V_FB=0V

V_CC= 12V, V_FB=0V

125

140

Internal MOSFET

R_DSON

mΩ

I_OUT= 2A

V_OUT= 5V

Efficiency

E_FFI

T_SD

I_OUT= 3A

Thermal Shutdown Temp.

Block Diagram

ºC

Pin Assignment

Name

Description

Feedback pin

H: Normal operation (Step-down)

L: Step-down operation stopped (All circuit deactivated)

Compensation pin

Switch pin. Connect external inductor/diode here

IC power supply pin

Comp

Vcc

Vss

Gnd pin

2/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Application Circuit

MLCC

Compensation Capacitor Selection (MLCC)

VIN

VOUT

5.0/3.3/2.5V

1.8/1.5V

2.2K

1nF

7~23V

7~20V

9~20V

9~18V

4~10V

15uH

10uH

15uH

10uH

330pF

560pF

330pF

1nF

1.2V

820pF

680pF

1nF

1.1V

1.0V

3.3/2.5V

6.8K

4.7K

1.8/1.5/1.2/ 1.1/1.0V

1nF

EL CAP

Compensation Capacitor Selection (EL CAP)

VIN

VOUT

7-20V

5.0/3.3/2.5/1.8V

Coil

3.9K

10nF

1nF

7-20V

5-7V

5-20V

1.8/1.5V

3.3/2.5/1.8/1.5/1.2V

Coil

SMD

0.82K

10nF

1nF

3/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Function Descriptions

PWM Control

The TS2509 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the

TS2509, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage produced

by the switching can easily be removed through a filter because the switching frequency remains constant. Therefore,

these converters provide a low-ripple power over broad ranges of input voltage and load current.

Setting the Output Voltage

Application circuit item shows the basic application circuit with TS2509 adjustable output version. The external resistor

sets the output voltage according to the following equation:

(EL CAP) Resistor select for output voltage setting

(MLCC) Resistor select for output voltage setting

V_OUT

1.3K

1.5K

2.2K

V_OUT

7.5K

15K

22K

27K

30K

56K

6.8K

4.7K

2.5K

39K

47K

33K

27K

15K

13K

3.3V

2.5V

1.8V

1.5V

1.2V

3.3V

2.5V

1.8V

1.5V

1.2V

2.2K

1.5K

2.5K

10K

Inductor Selection

For most designs, the operate with inductors of 10µH to 22µH. The inductor value can be derived from the following

equation:

L1 Recommend Value (V_IN=12V, I_OUT=3A)

V_OUT

1.8V

2.5V

3.3V

L1 Value

10~15uH

15~22uH

Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high

ripple currents. Choose inductor ripple current approximately 15% of the maximum load current 3A, ΔIL=0.4A. The DC

current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to

prevent core saturation (3A+0.2A).

Input Capacitor Selection

(EL CAP)

This capacitor should be located close to the IC using short leads and the voltage rating should be approximately 1.5

times the maximum input voltage. The RMS current rating requirement for the input capacitor of a buck regulator is

approximately 1⁄2 the DC load current. A low ESR input capacitor sized for maximum RMS current must be used. A

220µF low ESR capacitor for most applications is sufficient.

(MLCC)

A 22µF MLCC or two 10uF MLCC capacitors for most applications is sufficient.

4/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Function Descriptions (Continue)

Output Capacitor Selection

(EL CAP)

The output capacitor is required to filter the output and provide regulator loop stability. The important capacitor

parameters are; the 100KHz Equivalent Series Resistance (ESR), the RMS ripples current rating, voltage rating, and

capacitance value. For the output capacitor, the ESR value is the most important parameter. The ESR can be

calculated from the following formula.

_RIPPLE= ∆I_Lx ESR = 0.4A x 110mΩ = 44mV

An aluminum electrolytic capacitor's ESR value is related to the capacitance and its voltage rating. In most case, higher

voltage electrolytic capacitors have lower ESR values. Most of the time, capacitors with much higher voltage ratings

may be needed to provide the low ESR values required for low output ripple voltage. It is recommended to replace this

low ESR capacitor by using a 330µF low ESR values < 110mΩ

(MLCC)

A 33µF MLCC or three 10uF MLCC capacitors for most applications is sufficient.

R_DS(ON)Current Limiting

The current limit threshold is setting by the internal circuit.

V_IN

4.6V~6V

6V~10V

3.8A

10V~23V

4.0A

I_CL(MIN)

I_OUT(MAX)

2.5A

Layout Guidance

When laying out the PC board, the following suggestions should be taken to ensure proper operation of the TS2509.

These items are also illustrated graphically in below.

1. The power traces, including the PMOS Drain & Source trace, the Schottky and the C2 trace should be kept short,

direct and wide to allow large current flow.

2. Connect the C5 to the V_CC& EN pins of the TS2509 as closely as possible to get good power filter effect.

3. Keep the switching node, away from the sensitive FB node.

4. Connect ground side of the C2 & D1 as closely as possible.

5. Connect PMOS Source and R3 as closely as possible.

6. Do not trace signal line under inductor.

5/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Electrical Characteristics Curve

Figure 1. Feedback Voltage vs. Input Voltage

Figure 2.Quiescent Current vs. Input Voltage

Figure 3. Frequency vs. Input Voltage

Figure 4. Frequency vs. Temperature

Figure 5. Feedback Voltage vs. Temperature

Figure 6. Quiescent Current vs. Temperature

6/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Electrical Characteristics Curve

Figure 8.Output Ripple (V_IN=12V, V_OUT=5V, I_OUT=3A)

Figure 7. Efficiency

(V_IN=12V, V_OUT=5V, I_OUT=0.2A)

(V_IN=12V, V_OUT=5V, I_OUT=3A)

Figure 10.Power On test Wave

Figure 9.Power On test Wave

(V_IN=12V, V_OUT=5V, I_OUT=0.1~3A)

Figure 11. Load Transient Response

7/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

SOP-8 Mechanical Drawing

SOP-8 DIMENSION

MILLIMETERS

INCHES

MIN

DIM

MIN

4.80

3.80

1.35

0.35

0.40

MAX

5.00

4.00

1.75

0.49

1.25

MAX.

0.196

0.157

0.068

0.019

0.049

0.189

0.150

0.054

0.014

0.016

1.27BSC

0.05BSC

0.10

0º

0.25

7º

0.004

0º

0.009

7º

5.80

0.25

6.20

0.50

0.229

0.010

0.244

0.019

Marking Diagram

Y = Year Code

M = Month Code

(A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep,

J=Oct, K=Nov, L=Dec)

= Lot Code

8/9

Version: A09

TS2509

3A / 500KHz PWM Buck Converter

Notice

Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf,

assumes no responsibility or liability for any errors or inaccuracies.

Information contained herein is intended to provide a product description only. No license, express or implied, to any

intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of sale for

such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale

and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability,

or infringement of any patent, copyright, or other intellectual property right.

The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers

using or selling these products for use in such applications do so at their own risk and agree to fully indemnify TSC for

any damages resulting from such improper use or sale.

9/9

Version: A09

TS2509 [TSC]

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