RICOH RN5T562 Technical data

Step-down DC/DC with LDOs

RN5T562

Development Specifications

Rev.1.5

2009/05/14

RICOH COMPANY, LTD.

Electronic Devices Company

This specification is subject to change without notice.

RN5T562 Step-down DC/DC with LDOs

Table of Contents

1. Outline........................................................................................................................................... 3

2. Feature........................................................................................................................................... 3

3. Application.................................................................................................................................... 3

4. Ordering Information .................................................................................................................... 3

5. Block Diagram .............................................................................................................................. 4

6. Pin Configuration.......................................................................................................................... 4

7. Pin Description.............................................................................................................................. 5

8. Electrical Characteristics............................................................................................................... 6

8.1 Absolute Maximum Ratings .................................................................................................................... 6

8.2 Recommended Operating Conditions........................................................................................................ 6

8.3 Step-down DC/DC Converter Electrical Characteristics ............................................................................. 7

8.4 LDO1 Electrical Characteristics ............................................................................................................... 8

8.5 LDO2 Electrical Characteristics ............................................................................................................... 9

8.6 UVLO (Under Voltage Lock Out) Electrical Characteristics..................................................................... 10

8.7 Thermal Shutdown Circuit Electrical Characteristics ............................................................................... 10

8.8 DC Electrical Characteristics ................................................................................................................. 11

9. ON/OFF Control of LDOs and DC/DC ...................................................................................... 11

10. Step-down DC/DC Converter .................................................................................................. 12

10.1 Step-down DC/DC Converter Output Voltage Setting.............................................................................. 12

11. Typical Application and Application Hints ............................................................................. 13

12. Appendix.................................................................................................................................. 14

12.1 Reference Data of Step-down DC/DC Converter ..................................................................................... 14

13. Package Information ................................................................................................................ 16

RN5T562 Step-down DC/DC with LDOs

1. Outline

RN5T562 integrates CMOS-based step-down DC/DC converter and two low dropout regulators (LDOs) with low

supply current. A low ripple, high efficiency step-down DC/DC converter can be easily composed of this IC with

some external components such as inductor, capacitors and resistor. The self-oscillation frequency is up to 2MHz

and it allows DCDC to use small inductor and capacitor.

Output enable/disable of regulators is individually controllable through external pins. In addition, this IC has the

under voltage lockout function (UVLO), which powers off all the regulators with 2.20V (Typ.) UVLO threshold.

Also, RN5T562 has Thermal shutdown circuit which turns off all the regulators in the overheated state.

2. Feature

• Range of Input Voltage .............. 3.1V ~ 4.5V (DC/DC), 1.746V(1.8V-3.0%) ~ 4.5V (LDOs)

• Built-in Soft-start Function for DCDC

• Maximum Output Current.......... 500mA (DC/DC), 200mA (LDOs)

• Accuracy Output Voltage .......... ±3.0% (LDOs Output)

• Output Voltage (LDO1) ............ Settable in 0.05V step in range of 1.2V to 3.3V

• Output Voltage (LDO2) ............ Settable in 0.05V step in range of 1.2V to 3.3V

• Output Voltage (DC/DC) .......... Setting external resistance ratio in the range of 0.9V to 2.0V

• Thermal Shutdown Circuit

• UVLO

• Package ..................................... QFN 16pins, 3mm×3mm, t=0.8mm

• Process ...................................... CMOS

3. Application

• Power source for DMB.

• Power source for battery-powered equipment.

4. Ordering Information

RN5T562-XXXYYY

XXX : LDO1 Output Voltage.

YYY : LDO2 Output Voltage.

For example.

RN5T562-150180 : LDO1=1.50V, LDO2=1.80V.

RN5T562 Step-down DC/DC with LDOs

5. Block Diagram

The block diagram of the device is shown below.

6. Pin Configuration

QFN 16pins, 3mm×3mm, t=0.8mm

GND2

VFB

NC

Fig 5-1 Block Diagram

LX

11

TOP

VIEW

2

VIN1

PGND

10

3

VIN2

PVIN

12

13

14

15

16

1

VO1

DCON

9

8

7

6

5

4

VO2

LDO2ON

LDO1ON

VIN3

GND1

Fig 6-1 Pin Configuration

RN5T562 Step-down DC/DC with LDOs

7. Pin Description

No. Name I/O

1 VO1

2 VIN1

3 VIN2

4 VO2

5 GND1

6

7 LDO1ON

8 LDO2ON

9 DCON

10 PGND

11

12

13 GND2

14 VFB

15 NC - Non-connect. Connect to GND.

16 NC - Non-connect. Connect to GND.

VIN3

LX

PVIN

PWR

GND

PWR

GND

PWR

GND

Output voltage of LDO1.

O

Power supply for LDO1.

Power supply for LDO2.

Output voltage of LDO2.

O

GND for LDO block, UVLO, and TSHUT.

Power supply for DC/DC converter control block, UVLO, and TSHUT.

Input of LDO1 for ON/OFF.

I

Input of LDO2 for ON/OFF.

I

DC/DC ON/OFF control.

I

GND for DC/DC converter.

DC/DC converter switch output.

O

Power supply for DC/DC converter driver.

GND for DC/DC converter control block.

Output voltage feedback input of DCDC converter.

I

Function Notes

Table 7-1 Pin Description

RN5T562 Step-down DC/DC with LDOs

8. Electrical Characteristics

8.1 Absolute Maximum Ratings

The operation exceeding “Absolute Maximum Ratings” below may cause permanent damage to the device.

The operation of the device within the stated ratings below is not guaranteed.

Symbol Parameter Condition Rated Value Units

VIN Power Input Pin Voltage VIN1~3, PVIN pin -0.3~6.0 V

VLX LX Pin Voltage LX pin -0.3~4.5 V

V1 / V2 VO1, VO2 Pin Voltage VO1, VO2 pin -0.3~4.5 V

V

Input Voltage Range

PD

T

Storage Temperature - -55~+125 ℃

stg

Package

Allowable Dissipation

Note*1: Derate 17.27 [mW/℃] above +70℃.

Table 8-1 Absolute Maximum Ratings

DCON,

LDO1ON, LDO2ON

Mounted on Board,

=70℃

T

a

-0.3~VIN3+0.3 V

*1

950

mW

8.2 Recommended Operating Conditions

Symbol Parameter Condition Min Typ Max Units

VIN1 pin

- Power Supply Voltage1

VOUT1+0.3V＜1.746V

VIN1 pin

VOUT1+0.3V≧1.746

VIN2 pin

- Power Supply Voltage2

VOUT2+0.3V＜1.746V

VIN2 pin

VOUT2+0.3V≧1.746

- Power Supply Voltage3 VIN3 pin 3.1 4.5 V

-

Ta

DC/DC

Power Supply Voltage

Temperature of Operation

PVIN pin 3.1 4.5 V

- -40 +85 ℃

Table 8-2 Recommendation of Operation Conditions

1.746

(1.8-3%)

VOUT1

+0.3

1.746

(1.8-3%)

VOUT2

+0.3

4.5

V

4.5 V

4.5

V

4.5 V

RN5T562 Step-down DC/DC with LDOs

8.3 Step-down DC/DC Converter Electrical Characteristics

Operating Conditions (unless otherwise specified) VIN1, VIN2, VIN3, PVIN = 3.6V, Ta = 25℃ L1=2.2μH, C

OUT

=4.7μF

Symbol Parameter Condition Min Typ Max Units

- Input Voltage Range VIN3, PVIN pin 3.1 4.5 V

DVOUT Output Voltage Range - 0.9 2.0 V

DIOUT Output current VIN3=PVIN=3.1~4.5V 500 mA

DISS

Consumption

Current

DIOFF Standby Current

DILIM

Limit detection

Current

VIN3=PVIN=VFB=3.6V

DIOUT=0mA, no switching

VIN3=PVIN=4.5V

OFF state

- 800 mA

70 μA

1 μA

VFB FB Voltage - -1.5% 0.608 +1.5% V

ΔVFB

ΔVIN

ΔVFB

ΔT

*2

t

r

T

ONmin

FB Line Regulation

FB Voltage

Temperature

Coefficient

Soft-start Time - 120 μs

Minimum-On-Time - 120 ns

VIN3=PVIN=3.1~4.5V

DIOUT=DIOUTmax / 2

7 mV

-40℃≦Ta≦+85℃ ±100 ppm/℃

Table 8-3 Step-down DC/DC Converter Electrical Characteristics

Note*: Load Regulation, which is determined by DC resistance (DCR) on inductor, is given by: Load Regulation (Typ) = DCR (Ω)×DIOUT (A).

Note*1: When all regulators are off, Soft-start time will be added up with UVLO output delay time for releasing.

t

（Typ）= 120μs + 10μs（UVLO output delay time for releasing）.

r

RN5T562 Step-down DC/DC with LDOs

8.4 LDO1 Electrical Characteristics

Operating Conditions (unless otherwise specified) VIN1, VIN2, VIN3, PVIN = 3.6V, C

= 2.2μF, Ta = 25℃

OUT1

Symbol Parameter Condition Min Typ Max Units

- Input Voltage Range VIN1 pin

VOUT1*1

Output Voltage

Range

- 1.2 3.3 V

1.746

(1.8-3%)

4.5 V

IOUT1 Output Current - 200 mA

VIN1=VOUT1+0.3V

& IOUT1=IOUT1max,

VIN1=4.5V

& IOUT1=50μA

VIN1=1.746V

& IOUT1=IOUT1max,

VIN1=4.5V

&

-3 +3 %

&

VACC1

VOUT1+0.3V

≧1.746

Output Voltage

Accuracy

VOUT1+0.3V

＜1.746V

& IOUT1=50μA

ISHT1 Short Current VO1=0V 120 mA

VOUT1+0.3V≦VIN1

≦4.5V,

IOUT1=IOUT1max /2

1.746V≦VIN1≦4.5V,

IOUT1=IOUT1max /2

10 mV

ΔVOUT1

ΔVIN

Line Regulation

VOUT1+0.3V

≧1.746

VOUT1+0.3V

＜1.746V

ΔVOUT1

ΔIOUT1

ΔVOUT1

ΔT

a

Load Regulation

Output Voltage

Temperature

Coefficient

50μA＜IOUT1＜IOUT1max

VIN1=3.6V

-40℃≦T

30 mV

≦85℃ +100 ppm/℃

a

RR1 Ripple Rejection f=1kHz, IOUT1=IOUT1max / 2 60 dB

EN1 Output Noise (RMS)

BW=100Hz-100kHz

IOUT1=IOUT1max / 2

50 μVrms

ISS1 Supply Current IOUT1=0mA 70 μA

IOFF1 Standby Current IOUT1=0mA 1 μA

*2

C

Bypass Capacitor 0μA＜IOUT1＜200mA 2.2 μF

OUT1

*3

t

Rising Time

r1

tf1 Falling Time

IOUT1=0mA

VO1＞VOUT1×90%

IOUT1=0mA

VO1＜0.5V

10 μs

500 μs

Table 8-4 LDO1 Electrical Characteristics

Note*1: The output voltage will be fixed (with 0.05V step) by trimming at shipment.

Note*2: Bypass capacitor: 2.2μF, in the mounted state.

For optimized phase compensation, the bypass capacitor must be ceramic type.

Note*3: When all regulators are off, the rising time will be added up with UVLO output delay time for releasing.

t

（Typ）= 10μs + 10μs（UVLO output delay time for releasing）.

r1

RN5T562 Step-down DC/DC with LDOs

8.5 LDO2 Electrical Characteristics

Operating Conditions (unless otherwise specified) VIN1, VIN2, VIN3, PVIN = 3.6V, C

= 2.2μF, Ta = 25℃

OUT2

Symbol Parameter Condition Min Typ Max Units

- Input Voltage Range VIN2 pin

VOUT2*1

Output Voltage

Range

- 1.2 3.3 V

1.746

(1.8-3%)

4.5 V

IOUT2 Output Current - 200 mA

VIN2=VOUT2+0.3V

& IOUT2=IOUT2max,

&

VIN2=4.5V

& IOUT2=50μA

VIN2=1.746V

& IOUT2=IOUT2max,

&

VIN2=4.5V

-3 +3 %

VACC2

VOUT2+0.3V

≧1.746

Output Voltage

Accuracy

VOUT2+0.3V

＜1.746V

& IOUT2=50μA

ISHT2 Short Current VO2=0V 120 mA

VOUT2+0.3V≦VIN2

≦4.5V,

IOUT2=IOUT2max /2

1.746V≦VIN2≦4.5V,

IOUT2=IOUT2max /2

10 mV

ΔVOUT2

ΔVIN

Line Regulation

VOUT2+0.3V

≧1.746

VOUT2+0.3V

＜1.746V

ΔVOUT2

ΔIOUT2

ΔVOUT2

ΔT

Load Regulation 50μA＜IOUT2＜IOUT2max 30 mV

Output Voltage

a

Temperature

Coefficient

-40℃≦T

≦85℃ +100 ppm/℃

a

RR2 Ripple Rejection f=1kHz, IOUT2= IOUT2max / 2 60 dB

EN2 Output Noise (RMS)

BW=100Hz-100kHz

IOUT2= IOUT2max / 2

50 μVrms

ISS2 Supply Current IOUT2=0mA 70 μA

IOFF2 Standby Current IOUT2=0mA 1 μA

*2

C

Bypass Capacitor 0μA＜IOUT2＜200mA 2.2 μF

OUT2

*3

t

Rising Time

r2

tf2 Falling Time

IOUT2=0mA

VO2＞VOUT2×90%

IOUT2=0mA

VO2＜0.5V

10 μs

500 μs

Table 8-5

Table 8-6 LDO2 Electrical Characteristics

Note*1: The output voltage will be fixed (in 0.05V step) by trimming at shipment.

Note*2: Bypass capacitor: 2.2μF, in the mounted state.

For optimized phase compensation, the bypass capacitor must be ceramic type.

Note*3: When all regulators are off, the rising time will be added up with UVLO output delay time for releasing.

t

（Typ）= 10μs + 10μs（UVLO output delay time for releasing）.

r2

RN5T562 Step-down DC/DC with LDOs

8.6 UVLO (Under Voltage Lock Out) Electrical Characteristics

Operating Conditions (unless otherwise specified) Ta = 25℃

Symbol Parameter Condition Min Typ Max Units

V

Under voltage lock out threshold VCCVIN rising 2.25 V

Release

V

Under voltage lock out threshold VCCVIN falling 2.05 2.20 2.35 V

Detect

V

UVLO Hysteresis - 50 mV

HYS

Table 8-7 UVLO Electrical Characteristics

8.7 Thermal Shutdown Circuit Electrical Characteristics

Operating Conditions (unless otherwise specified) VIN1, VIN2, VIN3, PVIN = 3.6V

Symbol Parameter Condition Min Typ Max Units

T

DET

Detected

Temperature

- 140 ℃

T

Return Temperature - 110 ℃

RET

Table 8-8 Thermal Shutdown Circuit Electrical Characteristics

RN5T562 Step-down DC/DC with LDOs

8.8 DC Electrical Characteristics

Operating Conditions (unless otherwise specified) VIN1, VIN2, VIN3, PVIN = 3.6V, Ta = 25℃

Symbol Parameter Condition Min Typ Max Units

VT+

VT-

V

Schmitt Hysteresis Voltage

HIS

“H” Input Rising

Threshold Voltage (Schmitt)

“L” Input Rising

Threshold Voltage (Schmitt)

IIL Input Leakage Current

I

CCS

CCD

Shutdown Supply Current

(All output off)

No Load Supply Current

(All output on)

LDO1ON=0V, LDO2ON=0V

IOUT1,IOUT2,DIOUT=0mA

DCON,

LDO1ON, LDO2ON

DCON,

LDO1ON, LDO2ON

DCON,

LDO1ON, LDO2ON

DCON,

LDO1ON, LDO2ON

VIN1~3, PVIN =4.5V,

DCON=0V,

VIN1~3, PVIN =4.5V,

DVOUT =1.8V

DCON=3.6V,

LDO1ON=3.6V,

LDO2ON=3.6V

1.6 V

0.4 V

0.1 V

-3 3 μA

1 μA

210 μA

Table 8-9 DC Electrical Characteristics

Terminal Equivalent Circuit

VIN3

LDO1ON LDO2ON

DCON

Fig 8-1 Terminal Equivalent Circuit

9. ON/OFF Control of LDOs and DC/DC

RN5T562 has two Low Drop Output regulators (LDOs) and DC/DC converter. LDOs and DC/DC converter are

individually on/off controlled by each control pin; LDO1ON pin, LDO2ON pin and DCON pin.

The truth table is shown below.

State LDO1ON LDO2ON DCON

ON H H H

OFF L L L

Table 9-1 ON/OFF Control of LDOs and DC/DC

RN5T562 Step-down DC/DC with LDOs

10. Step-down DC/DC Converter

DC/DC converter turns on by DCON="H" (DC/DC enable signal). During standby mode, LX pin is high impedance.

When DC/DC becomes active, the internal Soft-start circuit is enabled and output voltage starts boosting. RN5T562

compares the internal reference voltage (typ.0.608V) and FB voltage. If FB voltage is below the reference voltage, it

turns on high-side switch by enabling one-shot circuit.

The high-side switch remains "ON" for the minimum-on-time and until FB voltage rises over the reference voltage, or

inductor current exceeds limit current. Once the high-side switch is disabled, it remains off until FB voltage falls below

the reference voltage, or inductor current falls below the limit current. During high-side switch is off, low-side switch

remains on until inductor current approaches 0. DC/DC converter regulates the output voltage by repeating the above

operation.

Therefore, oscillator frequency varies by input voltage, output voltage, output current and external circuit (R1, L, and

Cf). In addition, the feedback loop from LX pin through R1 and from DVOUT through C

eliminates phase lag, which

f

is brought by the output capacitor, and the stable loop and fast transient response are provided.

However, the equivalent series resistance causes output voltage to shift by output current. (Theoretically, output voltage

falls [IOUT(A)ｘDCR(Ω)])

10.1 Step-down DC/DC Converter Output Voltage Setting

DCDC Enable Signal

GND2

GND

VIN3

PVIN

One-shot

Circuit

Current

Switc hing C ontrol

Circuit

Limit

+

Vref

Soft-s tart

R1=R2*(DVOUT/V

DVOUT=Set output voltage

V

= 0.608V (Internal reference voltage)

FB

L

R1

L1=2.2µH

x 10

LX

FB

PGND

GND

C

f

GND

=

R1

R2

-1)

FB

DVOUT

C

f

Cout= 4.7µF

GND

Fig 10-1 Step-down DC/DC Converter Output Voltage Setting

External components example

- DVOUT=1.2V.

R1=220kΩ, R2=220kΩ, C

- DVOUT=1.8V.

R1=220kΩ, R2=110kΩ, C

=100pF

f

=100pF

f

RN5T562 Step-down DC/DC with LDOs

11. Typical Application and Application Hints

Fig 11-1 Typical Application and Application Hints

Symbol Item

L1 2.2μH R1 See section 9.1 R2 See section 9.1

Cf See section 9.1

C

4.7μF Ceramic Capacitor

OUT

C

2.2μF Ceramic Capacitor

OUT1

C

2.2μF Ceramic Capacitor

OUT2

C

1.0μF Ceramic Capacitor

IN1

C

4.7μF Ceramic Capacitor

IN2

Table 11-1 Examples of Components

Vendor Part number Inductance [μH] DCR [Ω]

FDK MIPW3226D2R2M 2.2 0.1

Table 11-2 Recommended External Inductor

RN5T562 Step-down DC/DC with LDOs

]

12. Appendix

12.1 Reference Data of Step-down DC/DC Converter

Operating Conditions VIN1, VIN2, VIN3, PVIN = 3.6V, T

L1: MIPW3226D2R2M (Vendor: FDK)

: C1608JB0J475K (Vendor: TDK)

C

OUT

DVOUT = 1.8V: R1=220kΩ, R2=220kΩ, Cf =100pF DVOUT = 1.2V: R1=220kΩ, R2=110kΩ, Cf =100pF

(1) Efficiency vs. Load Current

= 25℃ L1=2.2μH, C

a

DVOUT=1.8V

DVOUT=1.2V

OUT

=4.7μF

(2) Output Voltage vs. Load Current

1.230

1.220

1.210

1.200

1.190

Output Voltage [V

1.180

1.170

1.160

0 100 200 300 400 500

Load Current [mA]

Fig 12-1 Efficiency vs. Load Current

DVOUT=1.2V

1.840

1.830

1.820

1.810

1.800

1.790

Output Voltage [V

1.780

1.770

1.760

0 100 200 300 400 500

Fig 12-2 Output Voltage vs. Load Current

DVOUT=1.8V

Load Current [mA]

RN5T562 Step-down DC/DC with LDOs

(

(3) Light Load Switching Waveforms

DVOUT=1.2V, 10mA Load

DVOUT

LX

Time

400ns/div)

Fig 12-3 Light Load Switching Waveforms

(4) Heavy Load Switching Waveforms

DVOUT=1.2V, 300mA Load

DVOUT

LX

200ns/div)

Time

20mV/div AC Coupled

2V/div

20mV/div AC Coupled

2V/div

DVOUT

LX

DVOUT

LX

Time

DVOUT=1.8V, 10mA Load

20mV/div AC Coupled

2V/div

400ns/div)

DVOUT=1.8V, 300mA Load

20mV/div AC Coupled

2V/div

200ns/div)

Fig 12-4 Heavy Load Switching Waveforms

(5) Load Transient Response

DVOUT

10mA Load 10mA Load

500mA Load

Time (2μs/div)

Fig 12-5 Load Transient Response

DVOUT=1.2V

50mV/div AC Coupled

500mA/div

DVOUT=1.8V

DVOUT

50mV/div AC Coupled

500mA Load

10mA Load 10mA Load

500mA/div

Time (2μs/div)

RN5T562 Step-down DC/DC with LDOs

RICOH RN5T562 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual

1. Outline

2. Feature

3. Application

4. Ordering Information

5. Block Diagram

6. Pin Configuration

7. Pin Description

8. Electrical Characteristics

8.1 Absolute Maximum Ratings

8.2 Recommended Operating Conditions

8.3 Step-down DC/DC Converter Electrical Characteristics

8.4 LDO1 Electrical Characteristics

8.5 LDO2 Electrical Characteristics

8.6 UVLO (Under Voltage Lock Out) Electrical Characteristics

8.7 Thermal Shutdown Circuit Electrical Characteristics

8.8 DC Electrical Characteristics

9. ON/OFF Control of LDOs and DC/DC

10. Step-down DC/DC Converter

10.1 Step-down DC/DC Converter Output Voltage Setting

11. Typical Application and Application Hints

12. Appendix

12.1 Reference Data of Step-down DC/DC Converter

13. Package Information