R1232D301B_技术文档

R1232D SERIES

PWM STEP-DOWN DC/DC CONVERTER WITH SYNCHRONOUS RECTIFIER

NO.EA-129-0606

OUTLINE

The R1232D Series are CMOS-based PWM step-down DC/DC converters with synchronous rectifier, low

supply current. As an output capacitor, a 10µF or more ceramic capacitor can be used with the R1232D.

Each of these ICs consists of an oscillator, a PWM control circuit, a voltage reference unit, an error amplifier, a

soft-start circuit, protection circuits, a protection against miss operation under low voltage (UVLO), a chip enable

circuit, a synchronous rectifier, Nch. driver transistor, and so on. A low ripple, high efficiency step-down DC/DC

converter can be easily composed of this IC with only a few kinds of external components, or an inductor and

capacitors. (As for R1232D001x type, divider resistors are also necessary.) In terms of the output voltage, it is

fixed internally in the R1232Dxx1x types. While in the R1232D001x types, the output voltage is adjustable with

external divider resistors.

As protection circuits, current limit circuit which limits peak current of L^Xat each clock cycle, and latch type

protection circuit exist. The latch protection works if the term of the over-current condition keeps on a certain time.

Latch-type protection circuit works to latch an internal driver with keeping it disable. To release the condition of

protection, after disable this IC with a chip enable circuit, enable it again, or restart this IC with power-on or make

the supply voltage at UVLO detector threshold level or lower than UVLO.

FEATURES

• Two choices of Oscillator Frequency............................1MHz, 2.25MHz

(Small inductors can be used. 4.7µH for 1MHz/2.2µH for 2.25MHz)

•

Built-in Driver ON Resistance .......................................P-channel 0.2Ω (at VIN=5.0V)

• Built-in Soft-start Function.............................................Typ. 1.0ms (fosc=1MHz type)

• Output Voltage ..............................................................0.9V to 3.3V (xx1x Type)

0.8V to V^IN(001x Type)

• High Accuracy Output Voltage ......................................±2.0%

• Built-in Current Limit Circuit ..........................................Typ. 1.4A

• Package ........................................................................SON-8 (t=0.9mm)

APPLICATIONS

• Power source for portable equipment such as PDA, DSC, Notebook PC.

• Power source for HDD

1

R1232D

BLOCK DIAGRAMS

R1232Dxx1A/B

VDD

AGND

3

7

V^IN

2

8

Slope

Current Limit

Compensation

5

4

V^OUT

Phase

Compensation

Q

R

Vref

S

PWM

Output

Contorol

Error

L^X

Comparator

Amplifer

CE

Oscillator

Soft Start

UVLO

“H” Active

TEST Circuit

Chip Enable

1

6

“L” or GND Fixed

PGND

TEST

R1232D001C/D

VDD

AGND

3

7

V^IN

2

8

Slope

Current Limit

Compensation

5

4

V^FB

Phase

Compensation

Q

R

Vref

S

PWM

Output

Error

L^X

Comparator

Contorol

Amplifer

CE

Oscillator

Soft Start

UVLO

“H” Active

TEST Circuit

Chip Enable

1

6

“L” or GND Fixed

PGND

TEST

2

R1232D

SELECTION GUIDE

In the R1232D Series, the output voltage, the oscillator frequency, and the taping type for the ICs can be

selected at the user's request.

The selection can be made with designating the part number as shown below;

R1232Dxx1x-xx-x←Part Number

↑ ↑↑ ↑

↑

a b c

d

e

Code

Contents

Setting Output Voltage(V^OUT):

Stepwise setting with a step of 0.1V in the range of 0.9V to 3.3V is possible for fixed

output version."00" is for Output Voltage Adjustable version

(0.8V as the feedback voltage.)

a

b

1: fixed

Designation of Optional Function

A: 1MHz, Fixed Output Voltage

c

B: 2.25MHz, Fixed Output Voltage

C: 1MHz, Adjustable Output Voltage

D: 2.25MHz, Adjustable Output Voltage

Designation of Taping Type;

d

e

(Refer to Taping Specification)"TR" is prescribed as a standard.

Designation of Composition of pin plating

-F : Lead free plating

3

R1232D

PIN CONFIGURATION

SON-8

Top View

Bottom View

8

7

6

5

6

7

8

∗

1

2

3

4

3

2

1

PIN DESCRIPTIONS

Pin No

Symbol

PGND

VIN

Pin Description

1

2

3

4

5

6

7

8

Ground Pin

Voltage Supply Pin

VDD

CE

Chip Enable Pin (active with "H")

Output/Feedback Pin

VOUT/VFB

TEST

AGND

LX

Test Pin (Forced to the "L" or GND level.)

Ground Pin

LX Switching Pin (CMOS Output)

∗ Tab in the

parts have GND level. (They are connected to the reverse side of this IC.)

Do not connect to other wires or land patterns.

ABSOLUTE MAXIMUM RATINGS

Symbol

Item

Rating

6.5

Unit

V

VIN

VIN Supply Voltage

VDD Pin Voltage

VDD

6.5

V

VLX

LX Pin Voltage

V

−0.3 to V^IN+ 0.3

VCE

CE Pin Input Voltage

TEST Pin Input Voltage

VFB Pin Input Voltage

LX Pin Output Current

Power Dissipation (SON-8)*¹

Operating Temperature Range

Storage Temperature Range

V

VTEST

VFB

V

ILX

V

±1.5

480

PD

mW

°C

Topt

Tstg

−40 to 85

−55 to 125

∗1) For the power dissipation, refer to the package information on the website.

4

R1232D

ELECTRICAL CHARACTERISTICS

• R1232DxxxA/C

Topt=25°C

Unit

Symbol

Item

Conditions

Min.

Typ. Max.

VIN

Operating Input Voltage

2.6

5.5

V

V^IN=VCE=5.0V, IOUT=10mA

Step-down Output Voltage

Feedback Voltage

V

VFB

OUT

×0.980

0.784 0.800 0.816

×1.020

V

ppm/

°C

Step-down Output Voltage

∆VOUT/∆Topt

−40°C Topt 85°C

±150

=

Temperature Coefficient

fosc

IDD

Istandby

Oscillator Frequency

Supply Current

Standby Current

0.75

70

1.00

140

0.0

1.25

190

5.0

MHz

µA

V^IN=VCE =VSET +1.5V

V^IN=VCE =5.5V, VOUT=5.5V

V^CE=VOUT=0V, VIN= 5.5V

V^IN=5.5V,VCE=0V

V^LX=0V/5.5V

ILXleak

LX Leakage Current

0.0

5.0

−5.0

µA

RONP

RONN

ON Resistance of Pch Transistor

ON Resistance of Nch Transistor

Oscillator Maximum Duty Cycle

Soft-start Time

0.20

0.35

V^IN=5.0V, ILX=200mA

Ω

Maxduty

tstart

100

0.5

%

ms

1.0

2.0

1.4

V^IN=VCE =5.0V, at no load

V^IN=VCE =5.0V

tprot

Protection Delay Time

0.1

10.0

ms

A

ILXlimit

VUVLO1

Lx Current Limit

1.0

1.4

V^IN=VCE =5.0V

UVLO Detector Threshold

2.10

2.25

V^UVLO1

+0.10

2.40

2.50

0.1

V

V^IN=VCE =2.6V-> 1.5V

VUVLO2

ICE

UVLO Released Voltage

CE Input Current

2.20

−0.1

1.5

V

V^IN=VCE =1.5V-> 2.6V

V^IN=5.5V, VCE =5.5V/0V

V^IN=5.5V, VCE =0V,

V^OUT=5.5V/0V

V^IN=5.5V

V^IN=3.0V

µA

0.0

IVOUT

VOUT Leakage Current

0.0

0.1

VCEH

VCEL

CE "H" Input Voltage

CE "L" Input Voltage

V

0.3

VTESTL

TEST pin "L" Input Voltage

5

R1232D

• R1232DxxxB/D

Topt=25°C

Symbol

Item

Conditions

Min.

2.6

×0.980

Typ. Max.

5.5

Unit

V

VIN

VOUT

VFB

Operating Input Voltage

Step-down Output Voltage

Feedback Voltage

V^IN=VCE=5.0V,IOUT=10mA

×1.020

0.784 0.800 0.816

V

ppm/

°C

Step-down Output Voltage

∆VOUT/∆Topt

−40°C Topt 85°C

±150

=

Temperature Coefficient

fosc

IDD

Istandby

Oscillator Frequency

Supply Current

Standby Current

1.91

170

2.25

240

0.0

2.58

310

5.0

MHz

µA

V^IN=VCE=VSET+1.5V

VIN=VCE=5.5V, VOUT=5.5V

V^CE=VOUT=0V, VIN=5.5V

V^IN=5.5V, VCE=0V,

V^LX=0V/5.5V

ILXleak

LX Leakage Current

0.0

5.0

−5.0

µA

RONP

RONN

ON Resistance of Pch Transistor

ON Resistance of Nch Transistor

Oscillator Maximum Duty Cycle

Soft-start Time

0.20

0.35

V^IN=5.0V, ILX=200mA

Ω

Maxduty

tstart

100

0.15

0.1

%

ms

0.4

2.0

0.7

V^IN=VCE=5.0V, at no load

V^IN=VCE=5.0V

tprot

Protection Delay Time

10.0

ms

A

ILXlimit

VUVLO1

LX Current Limit

1.0

1.4

V^IN=VCE=5.0V

UVLO Detector Threshold

2.10

2.25

V^UVLO1

+0.10

2.40

2.50

0.1

V

V^IN=VCE=2.6V -> 1.5V

VUVLO2

ICE

UVLO Released Voltage

CE Input Current

2.20

−0.1

1.5

V

V^IN=VCE =1.5V -> 2.6V

V^IN=5.5V, VCE =5.5V/0V

V^IN=5.5V, VCE=0V,

V^OUT=5.5V/0V

V^IN=5.5V

V^IN=3.0V

µA

0.0

IVOUT

VOUT Leakage Current

0.0

0.1

VCEH

VCEL

CE "H" Input Voltage

CE "L" Input Voltage

TEST "L" Input Voltage

V

0.3

VTESTL

6

R1232D

TEST CIRCUIT

PGND

V^IN

L^X

A

AGND

V^DD

CE

TEST

V^FB

Test Circuit for Input Current and Leakage Current

PGND

V^IN

L^X

PGND

V^IN

L^X

V

AGND

V^DD

CE

V^DD

CE

TEST

V^FB

TEST

V^FB

A

Test Circuit for Supply Current and Standby Current

Test Circuit for ON resistance of L^X

PGND

V^IN

L^X

OSCILLOSCOPE

AGND

V^DD

CE

TEST

V^FB

Input Voltage, Output Voltage, Frequency, Lx Current Limit,

Protection Delay Time, UVLO Voltage Test Circuit

PGND

V^IN

L^X

OSCILLOSCOPE

AGND

V^DD

CE

TEST

V^FB

Soft Start Time Test Circuit

The bypass capacitor between power supply and GND is a ceramic capacitor 10µF.

7

R1232D

TYPICAL APPLICATION AND TECHNICAL NOTES

• Fixed Output Voltage Type

L

OUT

V

PGND

L^X

CIN

V^IN

V^DD

CE

AGND

LOAD

OUT

C

TEST

V^FB

• Adjustable Output Type

L

OUT

V

PGND

L^X

CIN

V^IN

V^DD

CE

AGND

LOAD

OUT

C

TEST

V^FB

Cb

R1

R2

CIN

COUT

10µF C2012JB0J106MT (TDK), 10µF CM21B106M06AB (Kyocera)

4.7µH/2.7µH VLP5610-4R7MR90, VLP5610-2R7M1R0 (TDK)

*2.2µH is also suitable for B version.

L

In terms of setting R1, R2, Cb, refer to the technical notes.

8

R1232D

When you use these ICs, consider the following issues;

• Input the same voltage into power supply pins, V^INand VDD. Set the same level as AGND and PGND.

• When you control the CE pin by another power supply, do not make its "H" level more than the voltage level

of V^IN/ VDD pin.

• Set external components such as an inductor, C^IN, COUT as close as possible to the IC, in particular,

minimize the wiring to V^INpin and PGND pin.

• At stand by mode, (CE="L"), the L^Xoutput is Hi-Z, or both P-channel transistor and N-channel transistor of

L^Xpin turn off.

• In terms of the protection circuits, current limit for the peak current of each cycle of Lx, and the latch

protection circuit, which works if the over-limit current flows continuously for a certain time exist. To release

the protection, once make this IC into be standby mode with chip enable pin, or make the supply voltage be

down to UVLO threshold level or less.

• Reinforce the V^IN, PGND, and VOUT lines sufficiently. Large switching current may flow in these lines. If the

impedance of V^INand PGND lines is too large, the internal voltage level in this IC may shift caused by the

switching current, and the operation might be unstable.

• Connect the TEST Pin to the "L" or GND level.

The performance of power source circuits using these ICs extremely depends upon the peripheral circuits.

Pay attention in the selection of the peripheral circuits. In particular, design the peripheral circuits in a way that

the values such as voltage, current, and power of each component, PCB patterns and the IC do not exceed their

respected rated values.

9

R1232D

OPERATION of step-down DC/DC converter and Output Current

The step-down DC/DC converter charges energy in the inductor when LX transistor is ON, and discharges the

energy from the inductor when L^Xtransistor is OFF and controls with less energy loss, so that a lower output

voltage than the input voltage is obtained. The operation will be explained with reference to the following

diagrams:

i1

OUT

I

L

Lx Tr

SD

OUT

V

IN

V

i2

CL

Step 1:P-channel Tr. turns on and current IL (=i1) flows, and energy is charged into C^L. At this moment,

IL increases from Ilmin (=0) to reach ILmax in proportion to the on-time period (ton) of P-channel Tr.

Step 2:When P-channel Tr. turns off, Synchronous rectifier N-channel Tr. turns on in order that L maintains IL at

ILmax, and current IL (=i2) flows.

Step 3:IL (=i2) decreases gradually and reaches IL=ILmin=0 after a time period of topen, and N-channel Tr.

Turns off. Provided that in the continuous mode, next cycle starts before IL becomes to 0 because toff

time is not enough. In this case, IL value increases from this Ilmin (>0).

In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton),

with the oscillator frequency (fosc) being maintained constant.

• Continuous Conduction Mode

The maximum value (ILmax) and the minimum value (ILmin) of the current flowing through the inductor are the

same as those when P-channel Tr. turns on and off.

The difference between ILmax and ILmin, which is represented by ∆I;

∆I=ILmax−ILmin=V^OUT×topen/L=(VIN−VOUT)×ton/L ........................................................Equation 1

Where,t=1/fosc=ton+toff

duty (%)=ton/t×100=ton×fosc×100

<

topen toff

=

In Equation 1, V^OUT×topen/L and (VIN−VOUT) ×ton/L are respectively shown the change of the current at ON,

and the change of the current at OFF.

Even if the output current (I^OUT) is, topen < toff as illustrated in the above diagram is not realized with this IC. At

least, topen is equal toff (topen=toff), and when I^OUTis further increased, ILmin becomes larger than zero

(ILmin>0). The mode is referred to as the continuous mode.

10

R1232D

In the continuous mode, when Equation 1 is solved for ton and assumed that the solution is tonc

tonc=t×V^OUT/VIN............................................................................................................. Equation 2

When the ton=tonc, the mode is the continuous mode.

OUTPUT CURRENT AND SELECTION OF EXTERNAL COMPONENTS

When P-channel Tr. of LX is ON:

(Wherein, Ripple Current P-P value is described as I^RP, ON resistance of P-channel Tr. and N-channel Tr. of LX

are respectively described as R^ONPand RONN, and the DC resistor of the inductor is described as RL.)

V^IN=VOUT+(RONP+RL)×IOUT+L×IRP/ton .............................................................................. Equation 3

When P-channel Tr. of L^Xis "OFF"(N-channel Tr. is "ON"):

L×I^RP/toff=VF+VOUT+RONN×IOUT ....................................................................................... Equation 4

Put Equation 4 to Equation 3 and solve for ON duty of P-channel transistor, Don=ton/(toff+ton),

D^ON=(VOUT−RONN×IOUT+RL×IOUT)/(VIN+RONN×IOUT−RONP×IOUT) ........................................... Equation 5

Ripple Current is as follows;

I^RP=(VIN−VOUT−RONP×IOUT−RL×IOUT)×DON/fosc/L .............................................................. Equation 6

wherein, peak current that flows through L, and LX Tr. is as follows;

ILmax=I^OUT+IRP/2 .......................................................................................................... Equation 7

Consider ILmax, condition of input and output and select external components.

ÌThe above explanation is directed to the calculation in an ideal case in continuous mode.

11

R1232D

How to Adjust Output Voltage and about Phase Compensation

As for Adjustable Output type, feedback pin (VFB) voltage is controlled to maintain 0.8V.

Output Voltage, V^OUTis as following equation;

V^OUTR1+R2=VFB:R2

V^OUT=VFB×(R1+R2)/R2

Thus, with changing the value of R1 and R2, output voltage can be set in the specified range.

In the DC/DC converter, with the load current and external components such as L and C, phase might be

behind 180 degree. In this case, the phase margin of the system will be less and stability will be worse. To

prevent this, phase margin should be secured with proceeding the phase. A pole is formed with external

components L and C^OUT.

fpole ~1/2π LCOUT

A zero (signal back to zero) is formed with R1 and Cb.

≅fzero ~ 1/(2p×R1×Cb)

First, choose the appropriate value of R1, R2 and Cb.

Set R1+R2 value 100kΩ or less.

For example, if L=4.7µH, C^OUT=10µF, the cut off frequency of the pole is approximately 23kHz.

To make the cut off frequency of the zero by R1, R2, and Cb be higher than 23kHz,

set R1=33kΩ and Cb=100pF.If V^OUTis set at 2.0V, R2=22kΩ is appropriate.

12

R1232D

External Components

1.Inductor

Select an inductor that peak current does not exceed ILmax. If larger current than allowable current flows,

magnetic saturation occurs and makes transform efficiency be worse.

Supposed that the load current is at the same, the smaller value of L is used, the larger the ripple current is.

Provided that the allowable current is large in that case and DC current is small, therefore, for large output

current, efficiency is better than using an inductor with a large value of L and vice versa.

2.Capacitor

As for CIN, use a capacitor with low ESR (Equivalent Series Resistance) Ceramic type of a capacity at least

10µF for stable operation.

C^OUTcan reduce ripple of the output voltage, therefore as much as 10µF ceramic type is recommended.

TIMING CHART

Output

Short

Output Short

CE pin Voltage

Intemal Opertional Intemal Soft-start

Amplifier Output

Set Voltage

Intemal Oscillator Waveform

Lx Pin Output

Latched

Delay Time of Protection

Soft-start Time

Stable

The timing chart as shown above describes the waveforms starting from the IC is enabled with CE and latched

with protection. During the soft-start time, until the level is rising up to the internal soft-start set voltage, the duty

cycle of L^Xis gradually wider and wider to prevent the over-shoot of the voltage. During the term, the output of

amplifier is "H". After the output voltage reaches the set output voltage, they are balanced well. Herein, if the

output pin would be short circuit, the output of amplifier would become "H" again, and the condition would

continue for 2.0ms (Typ.), latch circuit would work and the output of L^Xwould be latched with "OFF". (Output

="High-Z")

If the output short is released before the latch circuit works (within 2ms after output shorted), the output of

amplifier is balanced in the stable state again.

Once the IC is latched, to release the protection, input "L" with CE pin, or make the supply voltage at UVLO

level or less.

13

R1232D

TYPICAL CHARACTERISTICS

1) Output Voltage vs. Output Current (CIN = 10µF, COUT = 10µF)

R1232D121A

R1232D331A

V

IN=5.0V

VIN=5.0V

1.300

1.250

1.200

1.150

1.100

3.400

3.350

3.300

3.250

3.200

1

10

100

1000

1

10

100

1000

Output Current I^OUT(mA)

R1232D121B

R1232D331B

V

IN=5.0V

V

IN=5.0V

1.300

1.250

1.200

1.150

1.100

3.400

3.350

3.300

3.250

3.200

1

10

100

1000

1

10

100

1000

Output Current I^OUT(mA)

2) Efficiency vs. Output Current (CIN = 10µF, COUT = 10µF)

R1232D121A

R1232D331A

VIN=3.3V, 5.0V

VIN=5.0V

100

90

80

70

60

50

40

30

20

10

0

100

90

80

70

60

50

40

30

20

10

0

(VIN=5.0V)

(V^IN=3.3V)

1

10

100

1000

1

10

100

1000

Output Current I^OUT(mA)

R1232D121B

R1232D331B

14

R1232D

V

IN=3.3V, 5.0V

VIN=5.0V

100

90

80

70

60

50

40

30

20

10

0

100

90

80

70

60

50

40

30

20

10

0

(VIN=5.0V)

(V^IN=3.3V)

1

10

100

1000

1

10

100

1000

Output Current I^OUT(mA)

3) Output Waveform

R1232D121A

R1232D331A

V

IN=5.0V, IOUT=600mA

VIN=5.0V, IOUT=600mA

0.04

0.03

0.02

0.01

0

0.04

0.03

0.02

0.01

0

-0.01

-0.02

-0.03

-0.04

-0.01

-0.02

-0.03

-0.04

-3

-2

-1

0

1

2

3

-3

-2

-1

0

1

2

3

Time t(ns)

R1232D121B

R1232D331B

V

IN=5.0V, IOUT=600mA

VIN=5.0V, IOUT=600mA

0.06

0.04

0.02

0

0.04

0.03

0.02

0.01

0

-0.01

-0.02

-0.03

-0.04

-0.02

-0.04

-0.06

-1.5 -1.0 -0.5

0

0.5

1.0

1.5

-1.5 -1.0 -0.5

0

0.5

1.0

1.5

Time t(ns)

15

R1232D

4) Load Transient Response

R1232D121A

V

IN=5.0V

VIN=5.0V

0.8

0.6

0.4

0.5

0.4

0.3

0.2

0.1

0

0.8

0.6

0.4

0.2

0

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Output Current 10mA→600mA

Output Current 600mA→10mA

0.2

0

Output Voltage

-0.1

-0.2

-0.3

Output Voltage

-0.1

-50

0

50

100

150

200

-50

0

50

100

150

200

Time t (µs)

R1232D121B

V

IN=5.0V

VIN=5.0V

0.8

0.6

0.4

0.2

0

0.5

0.4

0.3

0.2

0.1

0

0.8

0.6

0.4

0.2

0

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Output Current 10mA→600mA

Output Current 600mA→10mA

Output Voltage

-0.1

-0.2

-0.3

Output Voltage

-0.1

-50

0

50

100

150

200

-50

0

50

100

150

200

Time t (µs)

5) Output Voltage vs. Input Voltage

R1232D121A

R1232D331A

I

OUT=600mA

I

OUT=600mA

1.22

1.21

1.20

1.19

1.18

3.32

3.31

3.30

3.29

3.28

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Input Voltage V^IN(V)

6) Oscillator Frequency vs. Input Voltage

R1232D121A

R1232D121B

16

R1232D

I

OUT=600mA

IOUT=600mA

1.10

1.05

1.00

0.95

0.90

2.4

2.3

2.2

2.1

2.0

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Input Voltage V^IN(V)

7) Lx Transistor On Resistance vs. Input Voltage

Switching Tr. Pch on Resistance

Synchronous Rectifier Tr. Nch on Resistance

I

OUT=200mA

IOUT=200mA

0.14

0.13

0.12

0.11

0.10

0.09

0.14

0.13

0.12

0.11

0.10

0.09

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Input Voltage V^IN(V)

8) Turn-on speed by CE pin

R1232D121A

VIN=5.0V, L=4.7µH Rload=12Ω

VIN=5.0V, L=4.7µH Rload=0Ω

CE

5V/div

VOUT

1V/div

IL

200mA/div

200µs/div

R1232D331B

17

R1232D

VIN=5.0V, L=2.7µH Rload=0Ω

VIN=5.0V, L=2.7µH Rload=33Ω

CE

5V/div

VOUT

V

OUT

1V/div

IL

200mA/div

100µs/div

9) Output Voltage vs. Temperature

R1232D121A

R1232D331A

V

IN=5.0V

VIN=5.0V

1.24

1.22

1.20

1.18

1.16

1.14

3.40

3.35

3.30

3.25

3.20

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

10) Oscillator Frequency vs. Temperature

R1232D121A

R1232D331B

V

IN=5.0V

VIN=5.0V

1.30

1.20

1.10

1.00

0.90

0.80

0.70

2.50

2.40

2.30

2.20

2.10

2.00

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

18

R1232D

11) Supply Current vs. Temperature

R1232D121A

R1232D331B

V

IN=5.0V

V

IN=5.0V

130

125

120

115

110

230

225

220

215

210

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

12) Soft-start time vs. Temperature

R1232D121A

R1232D331B

V

IN=5.0V, Rload=0Ω

VIN=5.0V, Rload=0Ω

1300

1100

900

600

550

500

450

400

350

300

700

500

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

13) UVLO Voltage vs. Temperature

R1232D121A

2.40

2.50

2.40

2.30

2.20

2.30

2.20

2.10

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

19

R1232D

14) CE Input Voltage vs. Temperature

R1232D121A

V

IN=5.0V, CE=H Threshold

VIN=5.0V, CE=L Threshold

1.5

1.3

1.0

0.8

0.5

1.5

1.3

1.0

0.8

0.5

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

15) TEST Input Voltage vs. Temperature

R1232D121A

VIN=5.0V

1.5

1.3

1.0

0.8

0.5

-40

-15

10

35

60

85

Temperature Topt(°C)

16) Lx Transistor On Resistance vs. Temperature

Driver Tr. Pch ON Resistance

Rectifier Tr.Nch ON Resistance

V

IN=5.0V

V

IN=5.0V

0.30

0.20

0.10

0.00

0.30

0.20

0.10

0.00

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

20

R1232D

17) Current Limit vs. Temperature

R1232D121A

R1232D331B

V

IN=5.0V

V

IN=5.0V

-0.80

-1.05

-1.30

-1.55

-1.80

-0.80

-1.05

-1.30

-1.55

-1.80

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

18) Protection Delay Time vs. Temperatures

R1232D121A

R1232D331B

V

IN=5.0V

VIN=5.0V

10.0

7.5

5.0

2.5

0.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

-40

-15

10

35

60

85

-40

-15

10

35

60

85

Temperature Topt(°C)

21

PE-SON-8-0510

PACKAGE INFORMATION

• SON-8

Unit: mm

PACKAGE DIMENSIONS

2.9 0.2

0.475TYP

8

+0.1

0.15

0.13 0.05

−0.15

5

1

4

Bottom View

Attention : Tab suspension leads in the

parts have V^DDor GND level. (They are

connected to the reverse side of this IC.)

Refer to PIN DISCRIPTION.

0.1

0.65

Do not connect to other wires or land patterns.

0.3 0.1

0.1 M

TAPING SPECIFICATION

4.0 0.1

+0.1

0

φ1.5

0.2 0.1

2.0 0.05

3.3

4.0 0.1

2.0MAX.

∅1.1 0.1

TR

User Direction of Feed

TAPING REEL DIMENSIONS

(1reel=3000pcs)

11.4 1.0

9.0 0.3

21 0.8

2 0.5

PE-SON-8-0510

PACKAGE INFORMATION

POWER DISSIPATION (SON-8)

This specification is at mounted on board. Power Dissipation (PD) depends on conditions of mounting on board.

This specification is based on the measurement at the condition below:

Measurement Conditions

Standard Land Pattern

Environment

Board Material

Board Dimensions

Copper Ratio

Mounting on Board (Wind velocity=0m/s)

Glass cloth epoxy plactic (Double sided)

40mm × 40mm × 1.6mm

Top side : Approx. 50% , Back side : Approx. 50%

Through-hole

φ0.5mm × 44pcs

Measurement Result

(Topt=25°C,Tjmax=125°C)

Standard Land Pattern

480mW

Free Air

300mW

Power Dissipation

Thermal Resistance

θja=(125−25°C)/0.48W=208°C/W

333°C/W

600

On Board

480

500

40

400

300

200

100

0

Free Air

0

25

50

75 85 100

125

150

Ambient Temperature (°C)

Power Dissipation

Measurement Board Pattern

IC Mount Area (Unit : mm)

RECOMMENDED LAND PATTERN

0.35 0.65

(Unit: mm)

ME-R1232D-0510

MARK INFORMATION

R1232D SERIES MARK SPECIFICATION

• SON-8

1

5

4

to

6

: Product Code (refer to Part Number vs. Product Code)

: Lot Number

,

1

2

3

5

4

6

R

• Part Number vs. Product Code

Product Code

Part Number

1

2

3

4

1

2

3

4

1

2

3

4

R1232D091A

R1232D101A

R1232D111A

R1232D121A

R1232D131A

R1232D141A

R1232D151A

R1232D161A

R1232D171A

R1232D181A

R1232D191A

R1232D201A

R1232D211A

R1232D221A

R1232D231A

R1232D241A

R1232D251A

R1232D261A

R1232D271A

R1232D281A

R1232D291A

R1232D301A

R1232D311A

R1232D321A

R1232D331A

K

0

1

2

3

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

A

R1232D091B

R1232D101B

R1232D111B

R1232D121B

R1232D131B

R1232D141B

R1232D151B

R1232D161B

R1232D171B

R1232D181B

R1232D191B

R1232D201B

R1232D211B

R1232D221B

R1232D231B

R1232D241B

R1232D251B

R1232D261B

R1232D271B

R1232D281B

R1232D291B

R1232D301B

R1232D311B

R1232D321B

R1232D331B

K

0

1

2

3

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

B

R1232D001C

R1232D001D

K

0

1

C

D


型号：	R1232D301B
厂家：	RICOH ELECTRONICS DEVICES DIVISION
描述：	PWM STEP-DOWN DC/DC CONVERTER WITH SYNCHRONOUS RECTIFIER PWM降压型DC / DC同步整流转换器转换器
文件：	总24页 (文件大小：844K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

R1232D301B [RICOH]

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