Richtek RT8206LGQW, RT8206LZQW, RT8206MGQW, RT8206MZQW Schematic

®

High Efficiency, Main Power Supply Controller for Notebook Computers

RT8206L/M

General Description

The RT8206L/M dual step-down, Switch-Mode Power-

Supply (SMPS) controller generates logic-supply voltages

in battery-powered systems. The RT8206L/M includes two

Pulse-Width Modulation (PWM) controllers fixed at 5V/

3.3V or adjustable from 2V to 5.5V. An optional external

charge pump can be monitored through SECFB (RT8206L).

This device also features a linear regulator providing a

fixed 5V output. The linear regulator provides up to 70mA

output current with automatic linear regulator bootstrapping

to the BYP input. The RT8206L/M includes on-board

power-up sequencing, the power good outputs, internal

soft-start, and internal soft-discharge output that prevents

negative voltages on shutdown.

A constant on-time PWM control scheme operates without

sense resistors and provides 100ns response to load

transients while maintaining a relatively constant switching

frequency. The unique ultrasonic mode maintains the

switching frequency above 25kHz, which eliminates noise

in audio applications. Other features include Diode-

Emulation Mode (DEM), which maximizes efficiency in

light-load applications, and fixed frequency PWM mode,

which reduces RF interference in sensitive application.

The RT8206L/M is available in a WQFN-32L 5x5 package.

Ordering Information

RT8206

Features

zz

z Wide Input Voltage Range 6V to 25V

zz

z Dual Fixed 5V/3.3V Outputs or Adjustable from 2V

zz

to 5.5V, 1.5% Accuracy

zz

z Secondary Feedback Input Maintains Charge Pump

zz

V oltage (RT8206L)

zz

z Independent Enable and Power Good

zz

z 5V Fixed LDO Output : 70mA

zz

z 2V Reference Voltage

zz

z Constant ON-Time Control with 100ns Load Step

zz

±±

±1% : 50

±±

μμ

μA

μμ

Response

zz

z Frequency Selectable via TON Setting

zz

z R

zz

Current Sensing and Progra mmable Current

DS(ON)

Limit

zz

z 4700ppm/

zz

z Selectable PWM, DEM or Ultrasonic Mode

zz

z Internal Soft-Start with Current Limiting and Soft-

zz

°°

°C R

°°

Current Sensing

DS(ON)

Discharge

zz

z High Efficiency Up to 97%

zz

z 5mW Quiescent Power Dissipation

zz

z Thermal Shutdown

zz

z RoHS Compliant and Halogen Free

zz

Applications

z Notebook and Sub-Notebook Computers

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

Package Type QW : WQFN-32L 5x5 (W-Type)

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

L : With SECFB M : Without SECFB

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.

DS8206L/M-07 June 2012 www.richtek.com

©

1

RT8206L/M

Marking Information

RT8206LGQW

RT8206LGQW : Product Number

RT8206L

YMDNN : Date Code

GQW YMDNN

RT8206LZQW RT8206MZQW

RT8206LZQW : Product Number

RT8206L

YMDNN : Date Code

ZQW YMDNN

Pin Configurations

(TOP VIEW)

RT8206MGQW

RT8206M GQW YMDNN

RT8206M ZQW YMDNN

RT8206MGQW : Product Number

YMDNN : Date Code

RT8206MZQW : Product Number

YMDNN : Date Code

VOUT2

FB2

ILIM2

32 31 30 29

1

REF BOOT2

2

TON

3

VCC

NC

VIN

LDO

NC

4

5

6

7

8

9101112 1413

BYP

VOUT1

ENLDO

FB1

SKIP

GND

ILIM1

PGOOD2

28 27 26 25

PGOOD1

EN2

33

EN1

PHASE2

UGATE2

24

23

22

21

20

19

18

17

1615

PHASE1

UGATE1

WQFN-32L 5x5

RT8206L

LGATE2

PGND

GND

SECFB

PVCC

LGATE1

BOOT1

VOUT2

FB2

ILIM2

32 31 30 29

1

REF BOOT2

2

TON

3

VCC

NC

VIN

LDO

NC

4

5

6

7

8

9101112 1413

BYP

VOUT1

ENLDO

FB1

SKIP

GND

ILIM1

PGOOD2

28 27 26 25

PGOOD1

EN2

33

EN1

PHASE2

UGATE2

24

23

22

21

20

19

18

17

1615

PHASE1

UGATE1

WQFN-32L 5x5

RT8206M

LGATE2

PGND

GND

NC

PVCC

LGATE1

BOOT1

©

DS8206L/M-07 June 2012www.richtek.com

2

Typical Application Circuit

C

1

µ

F

0

Q1

L

1 µ

H

.

8

V

1

T

U

O

V

5

3

C

2

µ

F

0

2

6

5

R

4

C

6

C

0

.

8

C

0

.

2

D

1

µ

F

D

4

1

µ

F

CP

Q3

C

1

D

V

P

0

3

0

1

R

1

2

0

k

9

C

1

C

R

C

2

F

µ

1

.

0

5

.

1

µ

F

7

C

.

1

µ

F

2

1

R 3

9

k

R

7

RT8206L/M

V

N

I

o

t

6

V

2

5

4

1

R

.

9

3

8

1

C

F

µ

.

1

0

4

0

15

0

3

17

16

18

10

9

C

1

µ

F

20

11

32

19

6

1

C

0

1

C

6

VIN

UGATE1

BOOT1

PHASE1

LGATE1

9

BYP

VOUT1

3

VCC

SECFB/NC

FB1

FB2

PVCC

7

LDO

RT8206L/M

PGOOD1

PGOOD2

UGATE2

BOOT2

PHASE2

LGATE2

PGND

VOUT2

REF

EN1

EN2

ENLDO

ILIM1

ILIM2

TON

SKIP

GND

26

24

25

23

22

30 1

13

28

14

27

4

12

31

2

29

21, 33 (Exposed Pad)

9

R

0

8

0

R

Q2

C

1

0

1

.

µ

F

Q4

1

C

5

2

.

0

µ

F

2

5

E

V

n

a

b

e

l

3

.

n

E

a

V

b

l

e

L

D

O

C

o

r

t

n

e

F

r

q

W

P

M

R

6

1

0

k

1

R

3

1

0

k

l

R

1

8

0

k

R

2

1

8

0

k

u

e

n

c

C

o

y

n

o

r

t

E

D

/

l

t

U

M

/

s

a

r

1

3

C

1

R

C

1

0

µ

L

4

7

.

1

0

1

4

V

P

V

2

F

1

0

µ

F

2

µ

H

C

1

7

2

0

C

ON

OFF

V

N

I

l

o

n

c

i

V

O

U

T

2

V

3

.

3

µ

F

Figure 1. Fixed Voltage Regulator

DS8206L/M-07 June 2012 www.richtek.com

©

3

RT8206L/M

1

C

µ

F

0

1

L 8

.

V

1

T

U

O

V

5

C

3

µ

F

0

2

3

2

C

0

2

C

F

µ

.

1

0

6

C

6

1

0

F

µ

.

C

8

0

1

F

µ

.

CP

5

1

R

1

5

k

6

1

R

1

0

k

V

N

I

o

6

t

V

5

2

4

1

R

.

3

9

8

1

C

F

.

µ

0

1

R

0

Q1

4

R

C

1 µ

H

Q3

R

5

4

C

2

F

.

µ

0

1

15

0

3

17

16

18

10

C

5

1

D

1

0

F

µ

.

D

2

C

7

C

3

D

1

0

F

µ

.

4

D

1

R 2

0

k

9

1

C

9

1

F

µ

20

2

1

R 3

9

k

11

V

P

C

R

7

19

6

C

1

0

C

1

6

VIN

UGATE1

BOOT1

PHASE1

LGATE1

9

BYP

VOUT1

3

VCC

SECFB/NC

FB1

PVCC

7

LDO

RT8206L/M

UGATE2

BOOT2

PHASE2

LGATE2

PGND

VOUT2

FB2

REF

PGOOD1

PGOOD2

EN1

EN2

ENLDO

ILIM1

ILIM2

TON

SKIP

GND

R

9

26

24

25

0

R

0

8

C

1

0

µ

.

23

22

30

32

1

C

1

5

0

2

.

µ

F

13

28

5

E

V

n

a

e

l

14

27

4

12

31

2

29

b

3

.

E

V

n

a

b

e

l

L

D

o

C

O

o

r

n

l

t

1

e

F

r

q

u

e

n

P

W

D

/

M

21, 33 (Exposed Pad)

Q2

F

Q4

6

R

1

0

k

R

1

3

1

0

k

R

1

8

0

k

R

2

8

0

k

c

y

o

C

n

o

r

t

E

t

U

l

/

M

a

r

s

1

C

3

C

1

0

µ

L

2

4

7

H

µ

.

1

R

0

C

1

4

P

V

C

P

V

C

2

F

1

0

µ

F

1

C

7

2

0

R

1

7

.

k

6

5

R

1

8

k

0

1

ON

OFF

V

I

N

l

o

n

c

i

V

O

U

T

2

3

V

.

F

µ

2

C

2

C

2

1

0

1

F

µ

.

Figure 2. Adjustable Voltage Regulator

4

©

DS8206L/M-07 June 2012www.richtek.com

Function Block Diagram

RT8206L/M

TON SKIP

BOOT1

UGATE1

PHASE1

LGATE1

PGND

VOUT1

FB1

ILIM1

PGOOD1

GND

BYP

LDO

VIN

PV

VINTON

CC

LDO

SMPS1

PWM Buck

Controller

SW Threshold

Internal

Logic

Thermal

Shutdown

Function Block Diagram

SMPS2

PWM Buck

Controller

Power-On Sequence

Clear Fault Latch

REF

PV

BOOT2

UGATE2

PHASE2

CC

LGATE2

VOUT2

FB2 ILIM2 PGOOD2

VCC

PVCC ENLDO EN1 EN2

REF

VOUT

REF

FB

PGOOD

+

1.1 x V

0.55 x V

0.9 x V

+

-

REF

On-Time Compute

T

Comp

+

Over-Voltage

+

-

+

Under-Voltage

+

Q

1-Shot

R

TRIG

Q

ON

TRIG

Fault

Latch

Blanking

Time

SS

Time

25kHz

Detector

Zero

Detector

SKIP

PWM Controller (One Side)

T

OFF

1-Shot

+

-

+

-

Current

Limit

UGATE

LGATE

V

CC

+

ILIM

-

PHASE

©

DS8206L/M-07 June 2012 www.richtek.com

5

RT8206L/M

Functional Pin Description

REF (Pin 1)

2V Reference Output. Bypass to GND with a 0.22μF

capacitor. REF can source up to 50μA for external loads.

Loading REF degrades FBx and output accuracy according

to the REF load-regulation error.

TON (Pin 2)

Frequency Select Input. (VOUT1/VOUT2 switching

frequency, respectively) :

TON = VCC, (200kHz / 300kHz)

TON = REF, (300kHz / 400kHz)

TON = GND, (400kHz / 500kHz)

VCC (Pin 3)

Analog Supply Voltage Input for the PWM Core. Bypass

to GND with a 1μF ceramic capacitor

ENLDO (Pin 4)

LDO Enable Input. REF and LDO are enabled if ENLDO

is within logic high level and disabled if ENLDO is less

than the logic low level.

NC (Pin 5, 8)

No Internal Connection.

VIN (Pin 6)

Power Supply Input. VIN is used for the constant on-time

PWM one shot circuits. VIN is also used to power the

linear regulators. The linear regulators are powered by

SMPS1 if VOUT1 is set greater than 4.66V and BYP is

tied to VOUT1. Connect VIN to the battery input and

bypass with a 1μF capacitor.

LDO (Pin 7)

Linear-Regulator Output. LDO can provide a total of 70mA

external loads. The LDO regulates a fixed 5V output. When

the BYP is within 5V switchover threshold, the internal

regulator shuts down and the LDO output pin connects to

BYP through a 1.5Ω switch. Bypass LDO output with a

minimum of 4.7μF ceramic.

BYP (Pin 9)

Switchover Source Voltage Input for LDO.

VOUT1 (Pin 10)

SMPS1 Output Voltage Sense Input. Connect this pin to

the SMPS1 output. VOUT1 is an input to the constant

on-time-PWM one-shot circuit. It also serves as the

SMPS1 feedback input in fixed-voltage mode.

FB1 (Pin 1 1)

SMPS1 Feedback Input. Connect FB1 to VCC or GND for

fixed 5V operation. Connect FB1 to a resistive voltage-

divider from VOUT1 to GND to adjust output from 2V to

5.5V.

ILIM1 (Pin 12)

SMPS1 Current Limit Adjustment. The GND − PHASE1

current-limit threshold is 1/10th the voltage seen at ILIM1

over a 0.5V to 2.5V range. There is an internal 5μA current

source from VCC to ILIM1. The logic current limit threshold

defaults to 100mV if ILIM1 is higher than (VCC − 1V).

PGOOD1 (Pin 13)

SMPS1 Power Good Open-Drain Output. PGOOD1 is low

when the SMPS1 output voltage is more than 10% below

the normal regulation point or during soft-start. PGOOD1

is in high impedance when the output is in regulation and

the soft-start circuit has terminated. PGOOD1 is low in

shutdown.

EN1 (Pin 14)

SMPS1 Enable Input. The SMPS1 will be enabled if EN1

is greater than the logic high level and disabled if EN1 is

less than the logic low level. If EN1 is connected to REF,

SMPS1 starts after SMPS2 reaches regulation (delay

start). Drive EN1 below 0.8V to clear fault level and reset

the fault latches.

UGA TE1 (Pin 15)

High Side MOSFET Floating Gate-Driver Output for

SMPS1. UGATE1 swings between PHASE1 and BOOT1.

6

©

DS8206L/M-07 June 2012www.richtek.com

RT8206L/M

PHASE1 (Pin 16)

Inductor Connection for SMPS1. PHASE1 is the internal

lower supply rail for the UGATE1 high side gate driver.

PHASE1 is the current-sense input for the SMPS1.

BOOT1 (Pin 17)

Boost Flying Capacitor Connection for SMPS1. Connect

to an external capacitor according to the typical application

circuits.

LGA TE1 (Pin 18)

SMPS1 Synchronous-Rectifier Gate-drive Output. LGATE1

swings between PGND and PVCC.

PVCC (Pin 19)

Supply Voltage for Low Side MOSFET driver LGATEx.

Connect a 5V power source to the PVCC pin (bypass

with 1μF MLCC capacitor to PGND if necessary). There is

an internal 10Ω connecting from PVCC to VCC. Make

sure that both VCC and PVCC are bypassed with 1μF

MLCC capacitors.

SECFB (Pin 20) (RT8206L)

Charge Pump Feedback Input. The SECFB is used to

monitor the optional external charge pump. Connect a

resistive voltage-divider from the charge pump output to

GND to detect the output. If SECFB drops below the

threshold voltage, an ultrasonic pulse occurs to refresh

the external charge pump driven by LGATE1 or LGATE2

NC (Pin 20) (RT8206M)

No Internal Connection.

LGA TE2 (Pin 23)

SMPS2 Synchronous-Rectifier Gate-drive Output. LGATE2

swings between PGND and PVCC.

BOOT2 (Pin 24)

Boost Flying Capacitor Connection for SMPS2. Connect

this pin to an external capacitor according to the typical

application circuits.

PHASE2 (Pin 25)

Inductor Connection for SMPS2. PHASE2 is the internal

lower supply rail for the UGATE2 high side gate driver.

PHASE2 is the current sense input for the SMPS2.

UGA TE2 (Pin 26)

High Side MOSFET Floating Gate-Driver Output for

SMPS2. UGATE2 swings between PHASE2 and BOOT2.

EN2 (Pin 27)

SMPS2 Enable Input. The SMPS2 will be enabled if EN2

is greater than the logic high level and be disabled if EN2

is less than the logic low level. If EN2 is connected to

REF, the SMPS2 starts after the SMPS1 reaches

regulation (delay start). Drive EN2 below 0.8V to clear

fault level and reset the fault latches.

PGOOD2 (Pin 28)

SMPS2 Power Good Open-Drain Output. PGOOD2 is low

when the SMPS2 output voltage is more than 10% below

the normal regulation point or during soft-start. PGOOD2

is high impedance when the output is in regulation and

the soft-start circuit has terminated. PGOOD2 is low in

shutdown.

GND [Pin 21, 33 (Exposed Pad)]

Analog Ground for both SMPS and LDO. The exposed

pad must be soldered to a large PCB and connected to

GND for maximum power dissipation.

PGND (Pin 22)

Power Ground for SMPS Controller. Connect PGND

externally to the underside of the exposed pad.

DS8206L/M-07 June 2012 www.richtek.com

©

SKIP (Pin 29)

SMPS Operation Mode Control.

SKIP = GND : DEM Mode operation

SKIP = REF : Ultrasonic Mode operation

SKIP = VCC : PWM Mode operation.

7

RT8206L/M

VOUT2 (Pin 30)

SMPS2 Output Voltage Sense Input. Connect this pin to

the SMPS2 output. VOUT2 is an input to the constant

on-time-PWM one-shot circuit. It also serves as the

SMPS2 feedback input in fixed-voltage mode.

ILIM2 (Pin 31)

SMPS2 Current-Limit Adjustment. The GND − PHASE2

current limit threshold is 1/10th the voltage seen at ILIM2

over a 0.5V to 2.5V range. There is an internal 5μA current

source from VCC to ILIM2. The logic current limit threshold

is default to 100mV value if ILIM2 is higher than (VCC −

1V).

FB2 (Pin 32)

SMPS2 Feedback Input. Connect FB2 to VCC or GND for

fixed 3.3V operation. Connect FB2 to a resistive voltage-

divider from VOUT2 to GND to adjust output from 2V to

5.5V.

8

©

DS8206L/M-07 June 2012www.richtek.com

RT8206L/M

Absolute Maximum Ratings (Note 1)

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

z PHASEx to GND

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

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

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

z VCC, ENx, SKIP, TON, PVCC, PGOODx, to GND ----------------------------------------------------- −0.3V to 6V

z LDO, FBx, VOUTx, SECFB, REF, ILIMx to GND -------------------------------------------------------- −0.3V to (V

z UGATEx to PHASEx

DC ------------------------------------------------------------------------------------------------------------------- −0.3V to (PVCC + 0.3V)

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

z LGATEx, BYP to GND

DC ------------------------------------------------------------------------------------------------------------------- −0.3V to (PVCC + 0.3V)

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

z PGND to GND ---------------------------------------------------------------------------------------------------- −0.3V to 0.3V

z Power Dissipation, P

@ TA = 25°C

D

WQFN-32L 5x5 -------------------------------------------------------------------------------------------------- 2.778W

z Package Thermal Resistance (Note 2)

WQFN-32L 5x5, θJA--------------------------------------------------------------------------------------------- 36°C/W

WQFN-32L 5x5, θJC-------------------------------------------------------------------------------------------- 6°C/W

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

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

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

z ESD Susceptibility (Note 3)

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

+ 0.3V)

CC

Recommended Operating Conditions (Note 4)

z Input Voltage, VIN ----------------------------------------------------------------------------------------------- 6V to 25V

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

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

DS8206L/M-07 June 2012 www.richtek.com

©

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Richtek RT8206LGQW, RT8206LZQW, RT8206MGQW, RT8206MZQW Schematic [ru]