Richtek RT8239AGQW, RT8239AZQW, RT8239BGQW, RT8239BZQW, RT8239CGQW Schematic

®

RT8239A/B/C

High Efficiency, Main Power Supply Controller for Notebook Computers

General Description

The RT8239A/B/C is a dual step down, Switch Mode Power

Supply (SMPS) controller which generates logic supply

voltages for battery powered systems. It includes two

Pulse Width Modulation (PWM) controllers adjustable

from 2V to 5.5V and also two fixed 5V/3.3V linear

regulators. One of the controllers (LDO5) provides

automatic switch over to the BYP1 input connected to

the main SMPS1 output for maximized efficiency. An

optional external charge pump can be monitored through

SECFB (RT8239B/C). Other features include on board

power up sequencing, a power good output, internal soft-

start, and a soft discharge output that prevents negative

voltage during shutdown.

A constant on-time PWM control scheme operates without

sense resistors and assures fast load transient response

while maintaining nearly constant switching frequency. To

eliminate noise in audio applications, an ultrasonic mode

is included, which maintains the switching frequency

above 25kHz. Moreover, a diode emulation mode

maximizes efficiency for light load applications. The

SMPS1/SMPS2 switching frequency can be adjustable

from 200kHz/233kHz to 400kHz/466kHz respectively.

The RT8239A/B/C is available in a WQFN-20L 3x3

package, and operates over an extended temperature range

from −40°C to 85°C.

Features

zz

z 5.5V to 25V Input Voltage Range

zz

z 2V to 5.5V Output Voltage Range

zz

z No Current Sense Resistor Needed

zz

z 5V/3.3V Linear Regulators

zz

z 4700ppm/

zz

z Internal Current Limit Soft-Start and Soft Discharge

zz

°°

°C R

°°

Current Sensing

DS(ON)

Output

zz

z Built In OVP/UVP/OCP

zz

z Selectable Operation Mode with Switcher Enable

zz

Control (RT8239A)

zz

z SECFB Input Maintains Charge Pump Voltage

zz

(RT8239B/C)

zz

z Power Good Indicator (RT8239B/C includes SECFB)

zz

z RoHS Compliant and Halogen Free

zz

Applications

z Notebook computers

z System Power Supplies

z 3- and 4- Cell Li+ Battery-Powered Device

Ordering Information

RT8239A/B/C

Package Type QW : WQFN-20L 3x3 (W-Type)

Lead Plating System G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free)

Pin Function With A : ENM B : SECFB C : SECFB, Ultrasonic Mode

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.

©

DS8239A/B/C-06 October 2012 www.richtek.com

1

RT8239A/B/C

Pin Configurations

BYP1

BOOT1

1

FB1

TON

FB2

2

3

GND

4

ENTRIP1

ENTRIP2

UGATE1

(TOP VIEW)

LGATE1

17181920

16

15

LDO3

14

LDO5

13

ENM

12

21

9876

ENLDO

115

VIN

10

FB1

ENTRIP1

TON

ENTRIP2

FB2

BYP1

BOOT1

PHASE1

UGATE1

LGATE1

17181920

16

1

2

3

GND

4

15

LDO3

14

LDO5

13

SECFB

12

21

9876

ENLDO

115

VIN

10

BOOT2

PGOOD

UGATE2

Marking Information

RT8239A

JB= : Product Code

JB=YM

DNN

JB YM

DNN

RT8239C

YMDNN : Date Code

JB : Product Code

YMDNN : Date Code

LGATE2

PHASE2 PHASE1

WQFN-20L 3x3

RT8239B

JC=YM

DNN

JC YM

DNN

BOOT2

PGOOD

PHASE2

UGATE2

RT8239B/CRT8239A

JC= : Product Code

YMDNN : Date Code

JC : Product Code

YMDNN : Date Code

LGATE2

JD= : Product Code

JD=YM

YMDNN : Date Code

DNN

JD : Product Code

JD YM

YMDNN : Date Code

DNN

2

©

DS8239A/B/C-06 October 2012www.richtek.com

Typical Application Circuit

V

N

I

5

t

V

.

o

2

5

V

R

C

1

0

µ

F

N1

1

V

O

T

U

1

+

V

5

C

3

C

5

µ

F

1

L

R

3

k

5

1

R

4

k

0

1

N2

Chip Enable

1

2

C

.

µ

1

0

2

R

4

C

.

0

1

R

TON

21 (Exposed Pad)

RT8239A/B/C

RT8239A

BOOT2

FB2

LDO3

LDO5

8

7

9

10

5

4

2

15

14

6

N3

5

R

C

7

0

1

µ

F

.

N4

8

R

k

0

1

R

9

k

0

1

C

9

4

.

7

µ

F

R10

100k

C10 10µF

11

VIN

12

F

µ

18

19

17

16

1

3

20

13

ENLDO

UGATE1

BOOT1

PHASE1

LGATE1

FB1

TON

BYP1

ENM

GND

UGATE2

PHASE2

LGATE2

ENTRIP2

ENTRIP1

PGOOD

C

6

1

0

µ

F

L

2

R

6

5

k

.

7

R

k

0

1

l

A

w

V

3

.

3

l

A

a

w

V

5

V

O

T

U

+

C

8

y

s

O

a

O

s

n

y

2

3

V

.

n

Figure 1. RT8239A NB Main Supply Typical Application Circuit

©

DS8239A/B/C-06 October 2012 www.richtek.com

3

RT8239A/B/C

V

N

I

5

.

V

t

2

o

5

V

C

1

0

µ

F

N1

1

V

O

U

T

1

+

V

5

3

C

5

C

F

µ

1

C

0

L

N2

3

R

k

5

1

4

R

k

0

1

3

1

µ

.

F

4

C

1

µ

.

F

C

V

CP

Figure 2. RT8239B/C NB Main Supply Typical Application Circuit

R

1

11

2

C

.

1

0

12

µ

F

18

2

R

C

4

.

0

19

F

µ

1

17

16

1

R

TON

3

20

1

C

0

1

F

µ

.

2

1

C

1

0

.

µ

F

1

R

2

0

k

5

1

13

2

1

R 3

9

k

VIN

ENLDO

UGATE1

BOOT1

PHASE1

LGATE1

FB1

TON

BYP1

SECFB

RT8239B/C

ENTRIP2

ENTRIP1

UGATE2

BOOT2

PHASE2

LGATE2

FB2

LDO3

LDO5

PGOOD

GND

8

5

R

7

C

9

0

10

5

4

2

15

C9

4.7µF

14

R10

6

100k

21 (Exposed Pad)

C

6

1

0

µ

N3

7

1

F

µ

.

L

N4

8

R

k

0

1

9

R

k

0

1

F

2

R

6

5

k

.

7

R

k

0

1

V

O

U

T

+

C

2

3

V

.

8

On

Off

n

s

y

a

O

l

A

V

w

.

3

n

O

y

l

s

w

a

V

A

C10 10µF

5

©

DS8239A/B/C-06 October 2012www.richtek.com

4

Functional Pin Description

Pin No. Pin Name Pin Function

1 FB1

2 ENTRIP1

3 TON ON-Time/Frequency Adjustment Input. Connect to GND with 56kΩ to 100kΩ.

4 ENTRIP2

5 FB2

6 PGOOD

7 BOOT2

8 UGATE2

9 PHASE2

10 LGATE2 Lower Gate Drive Output for SMSP2. LGATE2 swings between GND and LDO5.

11 VIN Supply Input for LDO5.

12 ENLDO

ENM (RT8239A)

13

14 LDO5

15 LDO3

16 LGATE1 Lower Gate Driver Output for SMPS1. LGATE1 swings between GND and LDO5.

17 PHASE1

SECFB (RT8239B/C)

SMPS1 Feedback Input. Connect FB1 to a resistive voltage divider from SMPS1 output to GND for adjustable output from 2V to 5.5V.

Channel 1 Enable and Current Limit Setting Input. Connect resistor to GND to set the threshold for Channel 1 synchronous R current limit threshold is 1/10th the voltage seen at ENTRIP1 over a 0.5V to 3V range. There is an internal 10μA current source from LDO5 to ENTRIP1. Leave ENTRIP1 floating or drive it above 4.5V to shut down channel 1.

Channel 2 Enable and Current Limit Setting Input. Connect resistor to GND to set the threshold for Channel 2 synchronous R current limit threshold is 1/10th the voltage seen at ENTRIP2 over a 0.5V to 3V range. There is an internal 10μA current source from LDO5 to ENTRIP2. Leave ENTRIP2 floating or drive it above 4.5V to shut down channel 2.

SMPS2 Feedback Input. Connect FB2 to a resistive voltage divider from SMPS2 output to GND for adjustable output from 2V to 5.5V.

Power Good Output for Channel 1 and Channel 2 (RT8239A).

Power Good Output for Channel 1, Channel 2 and SECFB (RT8239B/C).

Boost Flying Capacitor Connection for SMPS2. Connect to an external capacitor according to the typical application circuits.

Upper Gate Driver Output for SMPS2. UGATE2 swings between PHASE2 and BOOT2.

Switch Node for SMPS2. PHASE2 is the internal lower supply rail for the UGATE2 high side gate driver. PHASE2 is also the current sense input for the SMPS2.

Master Enable Input. LDO5/LDO3 is enabled if it is within logic high level and disabled if it is less than the logic low level. Leave ENLDO floating to default enable LDO5/LDO3.

Mode Selection with Enable Input. Pull up to LDO5 (Ultrasonic mode) or LDO3 (DEM) to turn on both switch Channels. Short to GND for shutdown.

Change Pump Feedback Pin. The SECFB is used to monitor the optional external charge pump. Connect a resistive divider from the change pump output to GND to detect the output. If SECFB drops below its feedback threshold, an ultrasonic pulse occurs to refresh the charge pump driven by LGATE1 or LGATE2. If SECFB drops below its UV threshold, the switcher channels stop working and enter into discharge-mode. Pull up to LDO5 or LDO3 to disable SECFB UVP function.

5V Linear Regulator Output. LDO5 is the supply voltage for the low side MOSFET driver and also the analog supply voltage for the device. Bypass a minimum 4.7μF ceramic capacitor to GND

3.3V Linear Regulator Output. Bypass a minimum 4.7μF ceramic capacitor to GND.

Switch Node SMPS1. PHASE1 is the internal lower supply rail for the UGATE1 high side gate driver. PHASE1 is also the current sense input for the SMPS1.

RT8239A/B/C

sense. The GND-PHASE1

DS(ON)

sense. The GND-PHASE2

DS(ON)

DS8239A/B/C-06 October 2012 www.richtek.com

©

5

RT8239A/B/C

Pin No. Pin Name Pin Function

18 UGATE1

19 BOOT1

20 BYP1 Switch Over Source Voltage Input for LDO5.

21 (Exposed Pad) GND

Function Block Diagram

Upper Gate Driver Output for SMPS1. UGATE1 swings between PHASE1 and BOOT1.

Boost Flying Capacitor Connection for SMPS1. Connect to an external capacitor according to the typical application circuits.

Analog Ground and Power Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation.

BOOT1

UGATE1

PHASE1

LGATE1

FB1

ENTRIP1

TON

BYP1

LDO5

SMPS1

10µA

-

Controller

On Time

+

LDO5

Switch Over Threshold

LDO5

PWM

Buck

SMPS2

PWM

Buck

Controller

REF

LDO5

LDO3

BOOT2

UGATE2

PHASE2

LDO5

LGATE2

10µA

FB2 ENTRIP2

ENM (RT8239A) SECFB (RT8239B/C)

PGOOD

GND

LDO3

VIN

ENLDO

©

Power-On Sequence

Clear Fault Latch

DS8239A/B/C-06 October 2012www.richtek.com

6

RT8239A/B/C

Absolute Maximum Ratings (Note 1)

z VIN, ENLDO to GND ------------------------------------------------------------------------------------------------------ −0.3V to 30V

z BOOTx to PHASEx ------------------------------------------------------------------------------------------------------- −0.3V to 6V

z ENTRIPx, FBx, TON, BYP1, PGOOD, LDO5, LDO3, ENM/SECFB to GND ------------------------------- −0.3V to 6V

z PHASEx to GND

DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 30V

< 20ns ----------------------------------------------------------------------------------------------------------------------- −8V to 38V

z UGATEx to PHASEx

DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 6V

< 20ns ----------------------------------------------------------------------------------------------------------------------- −5V to 7.5V

z LGATEx to GND

DC----------------------------------------------------------------------------------------------------------------------------- −0.3V to 6V

< 20ns ----------------------------------------------------------------------------------------------------------------------- −2.5V to 7.5V

z Power Dissipation, P

WQFN-20L 3x3 ------------------------------------------------------------------------------------------------------------ 3.33W

z Package Thermal Resistance (Note 2)

WQFN-20L 3x3, θJA------------------------------------------------------------------------------------------------------- 30°C/W

WQFN-20L 3x3, θJC------------------------------------------------------------------------------------------------------ 7.5°C/W

z Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------- 260°C

z Junction Temperature ----------------------------------------------------------------------------------------------------- 150°C

z Storage Temperature Range -------------------------------------------------------------------------------------------- −65°C to 150°C

z ESD Susceptibility (Note 3)

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

@ TA = 25°C

D

Recommended Operating Conditions (Note 4)

z Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 5.5V to 25V

z Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C

z Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C

Electrical Characteristics

(VIN = 12V, V

Input Supply

VIN Power On Reset

VIN Shutdown Current

VIN Standby Supply Current

Quiescent Power Consumption

SMPS Output and FB Voltage

FBx Regulation Voltage

ENLDO

= 5V, V

ENTRIPx

= 2V, V

= 5V, No Load on LDO5, LDO3, T

BYP1

= 25°C, unless otherwise specified)

A

Parameter Symbol Test Conditions Min Typ Max Unit

Rising Threshold -- 5.1 5.5

V

Falling Threshold 3.5 -- 4.5

I

VIN_SHDN

I

VIN_SBY

I

Q

V

Both SMPS Off -- 250 350

ENLDO

= GND

Both SMPSs on, FBx = 2.1V, BYP1 = 5V, ENM = 3.3V (RT8239A)

-- 20 40

μA

-- 5 7 mW

FBx, CCM Operation -- 2 --

V

FBx

FBx, DEM Operation 1.98 2.006 2.03

V

©

DS8239A/B/C-06 October 2012 www.richtek.com

7

RT8239A/B/C

Parameter Symbol Test Conditions Min Typ Max Unit

Output Voltage Adjustable Range

SECFB Voltage

On-Time

On-Time Pulse Width

Minimum Off-Time

Frequency Range

Ultrasonic Mode Frequency

Soft-Start

Soft-Start Time

Current Sense

Current Limit Current Source

Temperature Coefficient of I

ENTRIPx

Current Limit Adjustment Range

Current Limit Threshold

Zero-Current Threshold

Internal Regulator and Reference

LDO5 Output Voltage

LDO5 Output Current I

5V Switchover Threshold V

5V Switch R

R

DS(ON)

LDO3 Output Voltage V

LDO3 Output Current I

UVLO

LDO5 UVLO Threshold V

LDO3 UVLO Threshold V

Power Good

PGOOD Threshold V

PGOOD Propagation Delay t

SMPS1, SMPS2 2 -- 5.5

V

SECFB

t

UGATEx

t

LGATEx

f

SMPS1

f

SMPS2

f

ASM

t

SSx

I

ENTRIPx

V

ENTRIPx

V

ZC

V

LDO5

SHORT5

BYP1TH

BYPSW

LDO3

SHORT3

UVLO5

UVLO3

PGOOD

PD_PGOOD

RT8239B 1.92 2 2.08

= 20V

V

IN

R

= 56kΩ

TON

= 1.8V

FBx

SMPS1 Operating Frequency 200 -- 400

SMPS2 Operating Frequency 233 -- 466

RT8239C, V

Zero to 200mV Current Limit Threshold from ENTRIPx Enable

V

ENTRIPx

= 0.9V

On The Basis of 25°C

V

ENTRIPx

= I

GND − PHASEx, V

GND − PHASEx, FBx = 2.1V

V

= 0V, I

BYP1

V

= 0V, I

BYP1

6.5V < V V

BYP1

5.5V < V

V

BYP1

Falling Edge, Rising Edge with FB1 Regulation Point

V

BYP1

V

BYP1

V

BYP1

V

BYP1

Rising Edge -- 4.35 4.5

IN

= 0V, I

IN

= 0V, V

= 5V, I

= 0V, I

= 5V, I

= 0V, V

PHASEx

ENTRIPx

LDO5

< 25V

LDO5

< 25V

LDO5

LDO3

V

PHASE1

V

PHASE2

= 2V

= 50mV

x R

ENTRIPx

= 2V

< 100mA

< 100mA ,

< 50mA,

= 4.5V -- 225 -- mA

= 50mA -- 1.5 3 Ω

< 100mA 3.2 3.3 3.46 V

< 100mA 3.2 3.3 3.46

= 2.9V -- 150 -- mA

-- 256 --

-- 220 --

-- -- 400 ns

25 -- -- kHz

-- 2 -- ms

9.4 10 10.6

-- 4700 --

ppm/°C

0.5 -- 2.7 V

180 200 225 mV

-- 3 -- mV

4.8 5 5.2

4.75 -- 5.25

4.53 4.66 4.79 V

Falling Edge 3.9 4.05 4.2

Both SMPS Off -- 2.2 --

PGOOD Detect, Rising edge with soft-start delay time. Hysteresis = 2.5%

−14 −10 −6 %

Falling Edge -- 5 -- μs

V

ns

kHz

μA

V

8

©

DS8239A/B/C-06 October 2012www.richtek.com

Richtek RT8239AGQW, RT8239AZQW, RT8239BGQW, RT8239BZQW, RT8239CGQW Schematic [ru]