Richtek RT8202AGQW, RT8202APQW, RT8202BGQW, RT8202GQW, RT8202PQW Schematic [ru]

5 (1)

®

RT8202/A/B

Single Synchronous Buck Controller

General Description

The RT8202/A/B PWM controller provides high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, I/O, and chipset RAM supplies in notebook computers.

The constant on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns “instant-on” response to load transients while maintaining a relatively constant switching frequency.

The RT8202/A/B achieves high efficiency at a reduced cost by eliminating the current sense resistor found in traditional current mode PWMs. Efficiency is further enhanced by its ability to drive very large synchronous rectifier MOSFETs. The buck conversion allows this device to directly step down high voltage batteries for the highest possible efficiency. The RT8202/A/B is intended for CPU core, chipset, DRAM, or other low voltage supplies as low as 0.75V. RT8202 is available in WQFN-16L 4x4, RT8202A is available in WQFN-16L 3x3 and RT8202B is available in WQFN-14L 3.5x3.5 packages.

Features

Ultra-High Efficiency

Resistor Programmable Current Limit by Low Side RDS(ON) Sense (Lossless Limit) or Sense Resistor (High Accuracy)

Quick Load Step Response within 100ns

1% VOUT Accuracy over Line and Load

Adjustable 0.75V to 3.3V Output Range

4.5V to 26V Battery Input Range

Resistor Programmable Frequency

Over/Under Voltage Protection

2 Steps Current Limit During Soft-Start

Drives Large Synchronous-Rectifier FETs

Power Good Indicator

RoHS Compliant and 100% Lead (Pb)-Free

Applications

Notebook Computers

CPU Core Supply

Chipset/RAM Supply as Low as 0.75V

Pin Configurations

Ordering Information

 

(TOP VIEW)

 

 

TON

EN/DEM

NC

BOOT

 

 

RT8202/A/B

 

 

 

 

 

 

 

 

 

 

Package Type

 

16

15

14

13

 

 

VOUT

1

 

 

 

12

UGATE

QW : WQFN-16L 4x4 (W-Type) (RT8202)

 

 

 

VDD

2

 

 

 

11

PHASE

QW : WQFN-16L 3x3 (W-Type) (RT8202A)

GND

 

FB

3

 

10

OC

 

 

 

 

 

 

QW : WQFN-14L 3.5x3.5 (W-Type) (RT8202B)

PGOOD

4

 

17

9

VDDP

 

 

 

Lead Plating System

 

5

6

7

8

 

 

 

NC

GND

PGND

LGATE

 

 

P : Pb Free

 

 

 

 

 

 

 

 

 

 

G : Green (Halogen Free and Pb Free)

 

 

 

 

 

 

 

Note :

WQFN-16L 4x4/WQFN-16L 3x3

Richtek products are :

 

EN/DEM

 

BOOT

 

 

RoHS compliant and compatible with the current require-

 

 

 

 

 

 

 

 

 

 

 

ments of IPC/JEDEC J-STD-020.

TON

1

 

 

14

 

UGATE

Suitable for use in SnPb or Pb-free soldering processes.

2

 

 

 

13

VOUT

3

 

 

 

12

PHASE

 

 

 

 

Marking Information

VDD

4

GND

 

11

OC

FB

5

 

15

10

VDDP

 

 

 

PGOOD

6

 

 

 

9

LGATE

For marking information, contact our sales representative

 

7

 

 

8

 

 

 

GND

 

PGND

 

 

directly or through a Richtek distributor located in your

 

 

 

 

area.

WQFN-14L 3.5x3.5

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS8202/A/B-07 April 2014

www.richtek.com

 

1

Richtek RT8202AGQW, RT8202APQW, RT8202BGQW, RT8202GQW, RT8202PQW Schematic

RT8202/A/B

Typical Application Circuit

VDDP

5V

PGOOD

CCM/DEM

 

 

 

D1

 

 

 

VIN

 

 

 

 

 

 

BAT254

 

 

4.5V to 26V

 

 

 

 

C1

 

 

 

R3

 

 

 

 

 

 

1µF

 

 

 

1M

 

 

 

 

 

 

R2

 

 

 

R4

 

C4

 

 

 

 

51k

 

RT8202/A/B

 

10µF

 

 

 

 

2.2

 

 

 

 

 

 

TON

BOOT

 

 

C3

 

 

 

 

V

 

 

 

 

 

 

 

 

 

 

 

 

VDDP

 

R5

0

0.1µF

Q1

 

 

 

OUT

 

R1

 

UGATE

 

AO4702

L1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.4µH

 

 

 

 

10

 

PHASE

 

 

 

 

 

 

 

VDD

 

 

 

 

 

 

 

 

 

C2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C7

 

 

LGATE

 

 

 

R7

 

 

 

 

1µF

 

 

 

Q2

 

 

 

 

 

 

R6

10k

 

 

 

C6

220µF

 

 

PGOOD

OC

AO4702

C5

 

R8

 

 

 

 

 

 

 

 

 

EN/DEM

 

 

 

 

 

 

12k

 

 

 

 

FB

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

C8

 

R9

 

 

 

 

 

VOUT

 

 

 

0.1µF

 

20k

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PGND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1. Output Voltage Setting for VOUT < 3.3V Application

VDDP

5V

PGOOD

CCM/DEM

 

 

 

D1

 

 

 

VIN

 

 

 

 

 

 

BAT254

 

 

4.5V to 26V

 

 

 

 

C1

 

 

 

R3

 

 

 

 

 

 

 

1µF

 

 

 

1M

 

 

 

 

 

 

 

R2

 

 

 

R4

 

C4

 

 

 

 

51k

 

RT8202/A/B

 

10µF

 

 

 

 

2.2

 

 

 

 

 

 

TON

BOOT

 

 

C3

 

 

 

 

V

 

 

 

 

 

 

 

 

 

 

 

 

VDDP

 

R5

0

0.1µF

Q1

 

 

 

OUT

 

R1

 

UGATE

 

AO4702

L1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.4µH

 

 

 

 

10

 

PHASE

 

 

 

 

 

 

 

VDD

 

 

 

 

 

 

 

 

 

C2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C7

 

 

LGATE

 

 

 

R7

 

 

 

 

1µF

 

 

 

Q2

 

 

 

 

 

 

R6 10k

 

 

 

C6

220µF

 

 

PGOOD

OC

AO4702

C5

 

R8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EN/DEM

FB

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

C8

 

R9

 

 

 

 

 

 

 

 

0.1µF

 

 

 

 

 

 

VOUT

 

 

 

 

 

 

R10

 

 

PGND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V

 

OUT FB

R11

 

Figure 2. Output Voltage Setting for VOUT > 3.3V Application

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS8202/A/B-07 April 2014

2

 

RT8202/A/B

Functional Pin Description

Pin No.

Pin Name

Pin Function

RT8202/A

RT8202B

 

 

1

3

VOUT

VOUT Sense Input. Connect to the output of PWM converter. VOUT

is an input of the PWM controller.

 

 

 

2

4

VDD

Analog Supply Voltage Input for the internal analog integrated circuit.

Bypass to GND with a 1 F ceramic capacitor.

 

 

 

3

5

FB

VOUT Feedback Input. Connect FB to a resistor voltage divider from

VOUT to GND to adjust the output from 0.75V to 3.3V.

 

 

 

4

6

PGOOD

Power Good Signal Open-Drain Output of PWM Converter. This pin

will be pulled high when the output voltage is within the target range.

 

 

 

5, 14

--

NC

No Internal Connection.

6, 17

7, 15

GND

Ground for Analog Circuitry. The exposed pad must be soldered to a

(Exposed Pad)

(Exposed Pad)

large PCB and connected to GND for maximum power dissipation.

7

8

PGND

Power Ground.

8

9

LGATE

Low side N-MOSFET Gate-Drive Output for PWM. This pin swings

between GND and VDDP.

 

 

 

9

10

VDDP

VDDP is the gate driver supply for the external MOSFETs. Bypass to

GND with a 1 F ceramic capacitor.

 

 

 

10

11

OC

PWM Current Limit Setting and sense. Connect a resistor between

OC to PHASE for current limit setting.

 

 

 

11

12

PHASE

Inductor Connection. This pin is not only the zero-current-sense input

for the PWM converter, but also the UGATE high side gate driver

 

 

 

return.

12

13

UGATE

High Side N-MOSFET Floating Gate-Driver Output for the PWM

converter. This pin swings between PHASE and BOOT.

 

 

 

13

14

BOOT

Boost Capacitor Connection for PWM Converter. Connect an external

ceramic capacitor to PHASE and an external diode to VDDP.

 

 

 

 

 

 

PWM Enable and Operation Mode Selection Input. Connect to VDD

15

1

EN/DEM

for diode-emulation mode, connect to GND for shutdown mode and

 

 

 

floating the pin for CCM mode.

16

2

TON

VIN Sense Input. Connect to VIN through a resistor. TON is an input

of the PWM controller.

 

 

 

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS8202/A/B-07 April 2014

www.richtek.com

 

3

RT8202/A/B

Function Block Diagram

 

 

TRIG

 

 

 

 

 

 

 

VOUT

 

On-time

 

 

 

 

 

 

 

Compute

 

 

 

 

 

 

TON

 

 

 

 

 

 

 

 

1-SHOT

 

 

R

 

 

 

 

 

 

 

 

 

 

 

 

+

 

 

- Comp

 

 

BOOT

SS(Internal)

-

 

 

 

 

 

GM

 

 

 

S

Q

 

UGATE

 

+

-

 

 

+

DRV

 

 

 

 

 

PHASE

 

 

 

 

 

 

 

 

 

 

0.75V VREF

 

 

 

Min. TOFF

 

 

 

 

 

 

Q

TRIG

 

 

 

 

 

 

 

 

 

 

 

 

 

+

OV

Latch

1-SHOT

 

 

VDDP

 

115% VREF

S1

Q

 

 

DRV

LGATE

 

-

 

Latch

 

 

FB

 

-

UV

 

 

 

PGND

70% VREF

S1

Q

 

Diode

 

 

+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-

 

Emulation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

90% VREF

+

 

 

20uA

 

 

 

SS Timer

Thermal

 

 

 

VDD

 

 

 

+

OC

 

 

 

 

Shutdown

 

 

GND

 

 

 

 

 

 

 

-

 

 

 

EN/DEM

 

 

 

PGOOD

 

 

 

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS8202/A/B-07 April 2014

4

 

 

RT8202/A/B

Absolute Maximum Ratings (Note 1)

 

Input Voltage, TON to GND ----------------------------------------------------------------------------------------------

−0.3V to 32V

BOOT to GND --------------------------------------------------------------------------------------------------------------

−0.3V to 38V

PHASE to BOOT ----------------------------------------------------------------------------------------------------------

−6V to 0.3V

VDD, VDDP, VOUT, EN/DEM, FB, PGOOD to GND --------------------------------------------------------------

−0.3V to 6V

UGATE to PHASE --------------------------------------------------------------------------------------------------------

−0.3V to 6V

OC to GND ------------------------------------------------------------------------------------------------------------------

−0.3V to 32V

LGATE to GND -------------------------------------------------------------------------------------------------------------

−0.3V to 6V

PGND to GND --------------------------------------------------------------------------------------------------------------

−0.3V to 0.3V

Power Dissipation, PD @ TA = 25°C

 

WQFN-16L 4x4 ------------------------------------------------------------------------------------------------------------

1.852W

WQFN-16L 3x3 ------------------------------------------------------------------------------------------------------------

1.471W

WQFN-14L 3.5x3.5 -------------------------------------------------------------------------------------------------------

1.667W

Package Thermal Resistance (Note 2)

 

WQFN-16L 4x4, θJA -------------------------------------------------------------------------------------------------------

54°C/W

WQFN-16L 4x4, θJC ------------------------------------------------------------------------------------------------------

7°C/W

WQFN-16L 3x3, θJA -------------------------------------------------------------------------------------------------------

68°C/W

WQFN-16L 3x3, θJC ------------------------------------------------------------------------------------------------------

7.5°C/W

WQFN-14L 3.5x3.5, θJA --------------------------------------------------------------------------------------------------

60°C/W

WQFN-14L 3.5x3.5, θJC -------------------------------------------------------------------------------------------------

7°C/W

Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------

260°C

Junction Temperature ----------------------------------------------------------------------------------------------------

150°C

Storage Temperature Range --------------------------------------------------------------------------------------------

−65°C to 150°C

ESD Susceptibility (Note 3)

 

HBM (Human Body Mode) ----------------------------------------------------------------------------------------------

2kV

MM (Machine Mode) ------------------------------------------------------------------------------------------------------

200V

Recommended Operating Conditions

(Note 4)

Input Voltage, VIN ----------------------------------------------------------------------------------------------------------

4.5V to 26V

Supply Voltage, VDD, VDDP ----------------------------------------------------------------------------------------------

4.5V to 5.5V

Junction Temperature Range --------------------------------------------------------------------------------------------

−40°C to 125°C

Ambient Temperature Range --------------------------------------------------------------------------------------------

−40°C to 85°C

Electrical Characteristics

(VDD = VDDP = 5V, VIN = 15V, VOUT = 1.25V, EN/DEM = VDD, RTON = 1MΩ, TA = 25°C, unless otherwise specified)

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit

 

 

 

 

 

 

 

 

PWM Controller

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quiescent Supply Current

 

VDD + VDDP, FB = 0.8V

--

--

1250

A

 

 

 

 

 

 

 

 

TON Operating Current

 

RTON = 1M

 

--

15

--

A

 

 

VDD + VDDP

 

--

1

10

A

 

 

 

 

 

 

 

 

Shutdown Current

ISHDN

TON

 

--

1

5

A

 

 

EN/DEM = 0V

 

10

1

--

A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS8202/A/B-07 April 2014

www.richtek.com

 

5

RT8202/A/B

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit

 

 

 

 

 

 

 

 

FB Reference Voltage

VFB

VDD = 4.5 to 5.5V

 

0.742

0.75

0.758

V

 

 

 

 

 

 

 

 

FB Input Bias Current

 

FB = 0.75V

 

1

0.1

1

A

 

 

 

 

 

 

 

 

Output Voltage Range

VOUT

 

 

0.75

--

3.3

V

 

 

 

 

 

 

 

On-Time

 

VIN = 15V, VOUT = 1.25V, RTON = 1M

267

334

401

ns

 

 

 

 

 

 

 

 

Minimum Off-Time

 

 

 

250

400

550

ns

 

 

 

 

 

 

 

 

VOUT Shutdown Discharge

 

EN/DEM = GND

 

--

20

--

 

Resistance

 

 

 

 

 

 

 

 

 

Current Sensing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ILIM Source Current

 

LGATE = High

 

18

20

22

A

Current Comparator Offset

 

GND OC

 

10

--

10

mV

 

 

 

 

 

 

 

 

Current Limit Setting Range

RILIM

 

 

2.5

--

10

k

 

 

 

 

 

 

 

Zero Crossing Threshold

 

GND PHASE, EN/DEM = 5V

10

--

5

mV

 

 

 

 

 

 

 

 

Fault Protection

 

 

 

 

 

 

 

Current Limit Sense

VRILIM

GND PHASE, RILIM = 2.5k

35

50

65

mV

Voltage

GND PHASE, RILIM = 10k

170

200

230

 

 

 

 

 

 

 

 

 

 

 

 

 

Output UV Threshold

 

 

 

60

70

80

%

 

 

 

 

 

 

 

OVP Threshold

 

With respect to error comparator

10

15

20

%

 

threshold

 

 

 

 

 

 

 

 

OV Fault Delay

 

FB forced above OV threshold

--

20

--

s

 

 

 

 

 

 

 

VDD UVLO Threshold

 

Rising edge, Hysteresis = 20mV,

4.1

4.3

4.5

V

 

PWM disabled below this level

 

 

 

 

 

 

Soft-Start Ramp Time

 

From EN high to internal VREF reach

--

1.35

--

ms

 

0.71V (095%)

 

 

 

 

 

 

 

 

UV Blank Time

 

From EN signal going high

--

3.1

--

ms

 

 

 

 

 

 

 

 

Thermal Shutdown

 

 

 

--

155

--

°C

 

 

 

 

 

 

 

 

Thermal Shutdown

 

 

 

--

10

--

°C

Hysteresis

 

 

 

 

 

 

 

 

 

 

Driver On-Resistance

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UGATE Driver Pull Up

 

BOOT PHASE = 5V

 

--

1.5

5

 

 

 

 

 

 

 

 

 

UGATE Driver Sink

RUGATEsk

BOOT PHASE = 5V

 

--

1.5

5

 

 

 

 

 

 

 

 

LGATE Driver Pull Up

 

LGATE, High State (Source)

--

1.5

5

 

 

 

 

 

 

 

 

LGATE Driver Pull Down

 

LGATE, Low State (Sink)

--

0.6

2.5

 

 

 

 

 

 

 

 

UGATE Driver Source/Sink

 

UGATE PHASE = 2.5V,

--

1

--

A

Current

 

BOOT PHASE = 5V

 

 

 

 

 

 

 

LGATE Driver Source

 

LGATE forced to 2.5V

 

--

1

--

A

Current

 

 

 

 

 

 

 

 

 

LGATE Driver Sink Current

 

LGATE forced to 2.5V

 

--

3

--

A

 

 

 

 

 

 

 

Dead Time

 

LGATE Rising (PHASE = 1.5V)

--

30

--

ns

 

 

 

 

 

 

 

UGATE Rising

 

--

30

--

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Copyright ©2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS8202/A/B-07 April 2014

6

 

Loading...
+ 14 hidden pages