Datasheet UPC1933GR Datasheet (NEC)

DATA SHEET

BiCMOS INTEGRATED CIRCUIT

µ

µ

PC1933

µ µ

DC-DC CONVERTER CONTROL IC

DESCRIPTION

PC1933 is an IC that controls a low-voltage input DC-DC conver ter. This IC is suitable for an operation with3-V,

The

µ

3.3-V input or a lithium ion secondary battery input, because the minimum operating supply voltage is 2.5 V.
Because of its wide operating voltage range, it can also be used to control DC-DC converters that use an AC adapter for

input.

FEATURES

Low supply voltage: 2.5 V (MIN.)

•

Operating voltage range: 2.5 to 20 V (breakdown voltage: 30 V)

•

Timer latch circuit for short-circuit protection.

•

Ceramic capacitor with low capacitance (0.1

•

Open drain output (1 cannel: This output can be used to control a step-down converter, a step-up converter.)

•

Dead time is internally fixed to 85 %.

•

Soft start function (with a circuit to convert the timer latch circuit.)

•

ORDERING INFORMATION

Part Number Package

PC1933GR 8-pin plastic SOP (5.72 mm (225))

µ

F) can be used fo r short-circuit protection.

µ

The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.

Not all devices/types available in every country. Please check with local NEC representative for
availability and additional information.

Document No. G13690EJ3V0DS00 (3rd edition)
Date Published April 2000 NS CP (K)
Printed in Japan

The mark ★ shows major revised points.

1998

BLOCK DIAGRAM

µ

µ

PC1933

µ µ

FB

87 65

MOS input

Internal
fixed
voltage

12
I

I

E/A PWM

–
+

Timer latch for
short-circuit
protection section

DLY V

R

Oscillation
section

Soft start
select switch

DTC

(Internal fixed)

T

–
+
+

Reference
voltage
section

34

CC

OUTGND

MOS output

V

REF

2

Data Sheet G13690EJ3V0DS00

PIN CONFIGURATION (Top View)

8-pin plastic SOP (5.72 mm (225))

••••

µµµµ

PC1933GR

µ

µ

PC1933

µ µ

DLY

V

V

REF

I

I

CC

1

2

3

4

8

7

6

5

FB

R

T

GND

OUT

PIN FUNCTIONS

Pin No. Symbol Function Pin No. Symbol Function

1IIError amplifier inverted input 5 OUT Open-drain output
2 DLY Short-circuit protection 6 GND Ground
3VCCPower supply 7 R
4V

REF

Reference voltage output 8 FB Error amplifier output

T

Frequency setting resistor connection

Data Sheet G13690EJ3V0DS00

3

µ

µ

PC1933

µ µ

CONTENTS

1. ELECTRICAL SPECIFICATIONS................................................................................................................5

2. CONFIGURATION AND OPERATION OF EACH BLOCK....................................................................11

2.1 Reference V oltage Generator ...........................................................................................................................11

2.2 Oscillator ...........................................................................................................................................................11

2.3 Under Voltage Lock-out Circuit........................................................................................................................11

2.4 Error Amplifier...................................................................................................................................................11

2.5 PWM Comparator..............................................................................................................................................12

2.6 Timer Latch-Method Short Circuit Protection Circuit....................................................................................12

2.7 Output Circuit....................................................................................................................................................12

3. NOTES ON USE........................................................................................................................................13

3.1 Setting the Output Voltage ...............................................................................................................................13

3.2 Setting the Oscillation Frequency...................................................................................................................13

3.3 Preventing Malfunction of the Timer Latch-Method Short Circuit Protection Circuit..................................13

3.4 ON/OFF Control.................................................................................................................................................14

3.5 Maximum Duty Limit.........................................................................................................................................15

3.6 Notes on Actual Pattern Wiring........................................................................................................................15

4. APPLICATION EXAMPLE ......................................................................................................................... 16

4.1 Application Example.........................................................................................................................................16

4.2 List of External Parts........................................................................................................................................16

5. PACKAGE DRAWING................................................................................................................................17

6. RECOMMENDED SOLDERING CONDITIONS .......................................................................................18

4

Data Sheet G13690EJ3V0DS00

µ

µ

PC1933

µ µ

1. ELECTRICAL SPECIFICATIONS

====

Absolute Maximum Ratings (unless otherwise specified, TA

Parameter Symbol Ratings Unit
Supply voltage V
Output voltage V
Output current (open drain output) I
Total power dissipation P
Operating ambient temperature T
Storage temperature T

CC

O

O

T

A

stg

Caution Product quality may suffer if the absolute maximum rating is exceeded even momentarily for any

parameter. That is, the absolute maximum ratings are rated values at which the product is on the verge
of suffering physical damage, and therefore the product must be used under conditions that ensure
that the absolute maximum ratings are not exceeded.

25

°°°°

C)

30 V
30 V
21 mA

480 mW

−

20 to + 85

−

55 to + 150

°

C

°

C

Recommended Operating Conditions

Parameter Symbol Ratings Unit
Supply voltage V
Output voltage V
Output current I
Operating temperature T
Oscillation frequency f

CC

O

O

A

OSC

2.5 20 V
020V

20 mA

−

20

20 800 kHz

+

85

°

C

Caution The recommended operating range may be exceeded without causing any problems provided that the

absolute maximum ratings are not exceeded. However, if the device is operated in a way that exceeds
the recommended operating conditions, the margin between the actual conditions of use and the
absolute maximum ratings is small, and therefore thorough evaluation is necessary. The recommended
operating conditions do not imply that the device can be used with all values at their maximum values.

Data Sheet G13690EJ3V0DS00

5

µ

µ

PC1933

µ µ

Electrical Characteristics (unless otherwise specified, TA = 25

°°°°

C, VCC

====

3 V, f

OSC

= 100 kHz)

Block Parameter Symbol Conditions MIN. TYP. MAX. Unit

Under
voltage

Lock-out
section

Reference
Voltage
section

section

PWM

Start-up voltage V
Operation stop voltage V
Hysteresis voltage V
Reset voltage (timer latch) V
Reference voltage V

CC (L-H)

CC (H-L)

H

CCR

REF

Line regulation REG
Load regulation REG
Temperature coefficient

OSC

f

setting accuracy

OSC

f

total stabilit y

Maximum duty D

∆

V

OSC

∆

f

OSC

∆

f

MAX.

IN

L

REF

REF

I

= 0.1 mA 1.57 V

REF

I

= 0.1 mA 1.5 V

REF

I

= 0.1 mA 30 70 mV

REF

I

= 0.1 mA 1.0 V

REF

I

= 1 mA 2.0 2.1 2.2 V

2.5 V≤V

0.1 mA≤I

/∆T−20 °C≤T

RT = 18 k

−

20 °C≤T

2.5 V≤V

CC

≤

20 V 2 12.5 mV

REF

≤

1 mA 2 7.5 mV

A

≤+

Ω−

A

≤+

CC

≤

20 V

85 °C, I

85 °C,

REF

= 0 A 0.5 %

20

−

20

+
+

85 %

comparator
section
Error
Amplifier
section

Soft start time t

Input threshold voltage V
Input bias current I
Open loop gain A
Unity gain f
Maximum output voltage (+)
Maximum output voltage (−)
Output sink current I

Output source current I
Output
section

Drain cutoff current I

Output ON voltage V

Rise time t

Fall time t
Short-circuit
Protection
section

Input sense voltage V

UV sense voltage V

Source current on short-circuiting I

Delay time t
Overall Circuit operation current I

SS

ITH

B

v

unity

OM

V

OM

V

Osink

Osource

LEAK

OL

r

f

TH

UV

OUV

DLY

CC

+

−

DLY

C

= 0.1 µF50ms

0.285 0.3 0.315 V

−

100

+

VO = 0.3 V 70 80 dB
VO = 0.3 V 1.5 MHz
IO = −45 µA1.62V
IO = 45 µA 0.02 0.5 V
VFB = 0.5 V 0.8 1.4 mA
VFB = 1.6 V

−

70

−

VO = 30 V 100
RL = 150
RL = 150
RL = 150

Ω
Ω
Ω

0.2 0.6 V
50 ns
60 ns

1.75 1.92 2.05 V

0.8 0.85 V

1.0 1.6 2.7

DLY

C

= 0.1 µF50ms

VCC = 3 V 1.4 2.6 3.9 mA

30 %Oscillation
50 %

100 nA

µ

45

µ

µ

A
A

A

Caution Connect a capacitor of 0.01 to 10

µ

PC1933

6

µ

µ

F to the V

µ µ

REF

pin.

4

6

Data Sheet G13690EJ3V0DS00

C

REF

= 0.01 to 10 F

µ

Timing Chart

Data Sheet G13690EJ3V0DS00

Pin voltage

OUT

Soft start by C

Voltage of FB pin

Voltage of DLY pin

OFF ON Output oscillation

DLY

Soft start by C
finishing of soft- start, Switch

DLY

Detected

DTC (internal fixed)

Short-load

Voltage of DLY pin

is stopped

µ µ

µ

µ

PC1933

7

µ

µ

PC1933

µ µ

Typical Characteristic Curves (unless otherwise specified, VCC = 3 V, f

PT vs T

A

0.5

(W)

0.4

T

260.4 ° C/W

0.3

0.2

0.1

Total power dissipation P

0 25 50 75 100 125 150

Operating ambient temperature T

V

REF

vs T

A

2.13
I

REF

= 0 A

2.12

(V)

REF

2.11

A

(°C)

2.5

2.0

(V)

REF

1.5

1.0

0.5

Reference voltage V

1000

(kHz)

OSC

100

OSC

= 100 kHz, TA = 25

V

I

REF

= 0 A

REF

vs V

CC

°°°°

C) (Nominal)

012345

Supply voltage VCC (V)

f

OSC

vs R

T

2.10

2.09

2.08

Reference voltage V

2.07

–25 0 25 50 75 100

Operating ambient temperature T

∆f

OSC

vs T

A

6

RT = 18 kΩ

(%)

OSC

4

2

0

–2

–4

–6

Oscillation frequency accuracy ∆f

0–25 25 50 75 100

Operating ambient temperature T

A

(°C)

A

(°C)

10

Oscillation frequency f

1 10 100

T

Timing resistance R

VOL vs I

(kΩ)

O

0.5

0.4

(V)

OL

0.3

0.2

0.1

Output ON voltage V

0 5 10 15 20

O

Output current I

(mA)

8

Data Sheet G13690EJ3V0DS00

(V)

OL

0.4

0.3

0.2

IO = 20 mA

VOL vs T

µ

µ

PC1933

µ µ

D

MAX.

vs R

A

T

100

(%)

90

MAX.

80

70

0.1

Output ON voltage V

0

–25 0 25 50 75 100

Operating ambient temperature T

tSS vs C

DLY

600

500

(ms)

SS

400

300

200

100

Channel soft start time t

0 0.2 0.4 0.6 0.8 1.0

DLY pin capacitor capacitance C

t

DLY

vs T

A

60

DLY

A

(°C)

( F)

µ

60

Channel maximum duty D

50

1 10 100

T

(kΩ)

DLY

(ms)

600

DLY

Timing resistance R

t

DLY

vs C

500

400

300

200

100

0 0.2 0.4 0.3 0.4 1.0

Short-circuit protection circuit delay time t

DLY pin capacitor capacitance C

Av, vs f

φ

DLY

100

µ

( F)

180

50

40

(ms)

DLY

30

20

Delay time t

10

C

DLY

= 0.1 F

0

–25 0 25 50 75 100

Operating ambient temperature T

µ

A

(°C)

Data Sheet G13690EJ3V0DS00

80

60

(dB)

v

40

20

Gain A

φ

Av

0

–20

100 10 k1 k 10 M

Frequency f (Hz)

135

90

φ

45

0

Phase (deg)

–45

–90

1 M100 k

9

ICC vs V

3

(mA)

2

CC

1

Circuit operation I

0 5 10 15 20 25 30

Supply voltage V

CC

CC

(V)

ICC vs T

4

3

(mA)

CC

2

1

Circuit operation I

0

–25 0 25 50 75 100

Operating ambient temperature T

A

µ

µ

PC1933

µ µ

A

(°C)

10

Data Sheet G13690EJ3V0DS00

2. CONFIGURATION AND OPERATION OF EACH BLOCK

Figure 2-1 Block Diagram

µ

µ

PC1933

µ µ

8

FB

1

I

I

4

V

REF

CC

V

3

Dead time setting: 85 %

(internally fixed)

DLY

2

C

DLY

Error amplifier

0.3 V

Reference
voltage
section

Soft start
select switch

1.92 V

Under voltage
lock-out
section

SCP
comparator

Oscillation

section

PWM
comparator

Q

1

Q

2

Timer latch for
short-circuit
protection section

Output
section

SQ

Q

7

T

R

5

OUT

6

GND

2.1 Reference Voltage Generator

The reference voltage generator is comprised of a band-gap reference circuit, and outputs a temperature-compensated
reference voltage (2.1 V). The reference voltage can be used as the power supply for internal circuits, or as a reference
voltage, and can also be accessed externally via the V

REF

pin (pin 4).

2.2 Oscillator

The oscillator self-oscillates if a timing resistor is attached to the R

T

pin (pin 7 ). This oscilla tor waveform is i nput to the

inverted input pin of the PWM comparator to determine the oscillation frequency.

2.3 Under Voltage Lock-out Circuit

The under voltage lock-out circuit prevents malfunctioning of the internal circuits when the supply voltage is low, such as
when the supply voltage is first applied, or when the power supply is interrupted. When the voltage is low, the output
transistor is cut off at the same time.

2.4 Error Amplifier

The non-inverted input pin of the error amplifier is connected internally to 0.3 V (the input threshold voltage is 0.3 V
(TYP.)). The first stage of the error amplifier is a P-channel MOS transistor input.

Data Sheet G13690EJ3V0DS00

11

µ

µ

PC1933

µ µ

2.5 PWM Comparator

The output ON duty is controlled according to the outputs of the error amplifier.

A triangular waveform is input to the inverted pin, and the error amplifier output and Dead Time Control pin voltage (fixed
internally) are input to the non-inverted pins of the PWM comparator. Therefore, the output transistor ON period is the
period when the triangular waveform is lower than the error amplifier output and Dead Time Control pin voltage (fixed
internally) (refer to

2.6 Timer Latch-Method Short Circuit Protection Circuit

When the output of the converter drops, the non-inverted input pin (1 pin) voltage of the error amplifier drops, and the
FB output of the error amplifier of the output goes high. If the FB output exceeds the timer latch input detection voltage

TH

(V

= 1.92 V), then the output of the SCP comparator goes low, and Q1 goes off.

When Q
flip-flop. When the DLY pin voltage reaches the UV detection voltage (V
low, and the output stage is latched to OFF (refer to

Make the power supply voltage briefly less than the reset voltage (V

1

Timing Chart

turns OFF, the constant-current supply charges C

).

DLY

via the DLY pin. The DLY pin is internally connected to a

UV

= 0.7 V (TYP.)), the output Q of the flip-flop goes

Figure 2-1 Block Diagram

CCR

).

, 1.0 V TYP.) to reset the latch circuit when the

short-circuit protection circuit has operated.

2.7 Output Circuit

The output circuit has an N-channel open-drain output providing an output withstand voltage of 30 V (absolute maximum
rating), and an output current of 21 mA (absolute maximum rating).

12

Data Sheet G13690EJ3V0DS00

µ

µ

PC1933

µ µ

3. NOTES ON USE

3.1 Setting the Output Voltage

Figure 3-1 illustrates the method of setting the output voltage. The output voltage is obtained using the formula shown in
the figure.

The input threshold value of the error amplifier is 0.3 V (TYP.) for the error amplifier. Therefore, select a resistor value
that gives this voltage.

Figure 3-1 Setting the Output Voltage

1

OUT

(positive voltage) V

V

R

1

C

R

NF

2

R

NF

OUT

1

8

E/A

0.3 V

= 1 +

R

• 0.3

R

2

3.2 Setting the Oscillation Frequency

Choose R

T

according to the oscillation frequency (f

Characteristics Curves f

OSC

.) The formula below (3-1) gives an approximation of f

T

vs R

OSC

) vs timing resistor (RT) characteristics (refer to

OSC

. However, the result of

Typical

formula 3-1 is only an approximation, and the value must be confirmed in actual operation, especially for high-frequency
operation.

OSC

f

[Hz] ≅ 1.856 x 109/RT[Ω] (3-1)

3.3 Preventing Malfunction of the Timer Latch-Method Short Circuit Protection Circuit

The timer latch short-circuit protection circuit operates when the error amplifier output (pin 8) exceed approximately 1.92
V, and cuts off the output. However, if the rise of the power supply voltage is fast, or if there is noise on the DLY pin (pin 2),
the latch circuit may malfunction and cut the output off.

To prevent this, lower the wiring impedance between the DLY pin and the GND pin (pin 6), and avoid applying noise to
the DLY pin.

Data Sheet G13690EJ3V0DS00

13

µ

µ

PC1933

µ µ

3.4 ON/OFF Control

The ON/OFF control method of the output oscillation is to input the ON/OFF signal from ON as shown in Figure 3-2.
Soft start or timer latch (SCP) is internally selected. Soft start is executed when the first start signal is input. When the
end of soft start is detected, the soft start select switch is turned OFF and the timer latch circuit operates.

Figure 3-2 ON/OFF Control

V

O

D

1

(Converter
output
voltage)

R

1

I

I

2

R

–
+

0.3 V

Dead time
setting: 85 %
(internally fixed)

FB

Error amplifier

V

REF

R

SCP comparator

+
–

0.63 V

+
+
–

PWM comparator

Q

To output stage

ON Q

1

C

DLY

SW

Oscillation section

(common to each channel)

DLY

(1) When ON

1

Q

: ON → DLY pin: Low level → Output duty of PWM comparator: 0 %

is high: OFF status

D1: ON → II pin: High level → FB output: Low level

(2) When ON is low: ON status (start up)

: OFF → C

Q

1

D

: OFF → II pin: Low level → FB output: High level

1

(3) When ON

1

Q

: ON → DLY pin: Low level (Nothing happens because SW is OFF.)

1

D

: ON → II pin: High level → FB output: Low level → PWM comparator output duty: 0 %

is charged in the sequence of [V

DLY

goes high again after start up (SW: OFF): OFF status

Converter output voltage (VO) drops.

→

→ R1 → SW → DLY pin → C

REF

] → Soft start

DLY

Caution Even if start up is executed by making ON low again after (3), soft start is not executed because the

CC

to 0 V once.

14

soft start select switch (SW) remains OFF. To execute soft start again, drop V

Data Sheet G13690EJ3V0DS00

µ

µ

PC1933

µ µ

3.5 Maximum Duty Limit

PC1933 is switched internally between Soft Start and Timer Latch. For this reason, the DTC voltage is fixed internally,

µ

and the maximum duty is limited to 85%.

3.6 Notes on Actual Pattern Wiring

When actually carrying out the pattern wiring, it is necessary to separate control-related grounds and power-related
grounds, and make sure that they do not share impedances as far as possible. In addition, make sure the high-frequency
impedance is lowered using capacitors and other components to prevent noise input to the V

REF

pin.

Data Sheet G13690EJ3V0DS00

15

4. APPLICATION EXAMPLE

4.1 Application Example

Figure 4-1 shows an example circuit for obtaining +5 V/50 mA from a +3 V power supply.

Figure 4-1 Application Example

COM

V

IN

= 3 V

C

5

µ

C

3300

pF

30 kΩ

F1

R2 47 kΩ R6 470 Ω

5

150 Ω

R

T

3.9 kΩ

5876

OUTR

T

FB

1

I

R

1

I

µ

PC1933

DLY V

GND

CCVREF

R

20 kΩ

R

3

2.4 kΩ
VR

4

1 kΩ

C

2

7

R

100 C3 100 pF

pF

R

8

7.5 kΩ

4123

C

DLY

C

0

µ

F0.1

µ

F0.1

1

µ

H47

L

9

68 Ω

R

Q

1

Q

2

R

10

20 kΩ

µ

µ

PC1933

µ µ

V

O

= + 5 V

O

= 50 mA

D

1

Q

3

I

C

4

µ

F68

COM

4.2 List of External Parts

The list below shows the external parts.

Table 4-1 List of External Parts

Symbol Parameter Function Part number Maker Remark

4

C

1

D

1

L

3

Q

1

Q

2

Q

68 µ F Output capacitor 20SA68M SANYO OS-CON, SA series

Schottkey diode D1FS4 SHINDENGEN

47 µ H Choke inductor 636FY-470M TOKO D73F series

Switching transistor 2SD2403 NEC
Buffer transistor 2SC1623 NEC
Buffer transistor 2SA812 NEC

Remarks 1. The capacitors that are not specified in the above list are multilayer ceramic capacitors.

2. The resistors that are not specified in the above list are 1/4W resistors.

16

Data Sheet G13690EJ3V0DS00

5. PACKAGE DRAWING

8-PIN PLASTIC SOP (5.72 mm (225))

85

detail of lead end

P

µ

µ

PC1933

µ µ

1

4

A

F

G

S

B

C

M

D

M

E

NOTE

Each lead centerline is located within 0.12 mm of
its true position (T.P.) at maximum material condition.

H

I

J

L

K

ITEM

A
B

C
D

E
F

G

H

I
J

K

L

M

N
P

SN

MILLIMETERS

+0.17

5.2

−0.20

0.78 MAX.

1.27 (T.P.)
+0.08

0.42

−0.07

0.1±0.1

1.59±0.21

1.49

6.5±0.3

4.4±0.15

1.1±0.2
+0.08

0.17

−0.07

0.6±0.2

0.12

0.10

+7°

3°

−3°

S8GM-50-225B-6

Data Sheet G13690EJ3V0DS00

17

6. RECOMMENDED SOLDERING CONDITIONS

Recommended solder conditions for this product are described below.

µ

µ

PC1933

µ µ

For details on recommended soldering conditions, refer to Infor mation Document

Technology Manual” (C10535E)

For soldering methods and conditions other than those recommended, consult NEC.

Surface Mount Type

µ

µ

PC1933GR: 8-pin plastic SOP (5.72 mm (225))

µ µ

Soldering Method Soldering Conditions Symbol of Recommended

Infrared reflow Package peak temperature: 235 °C, Time: 30 seconds MAX. (210 °C MIN.),

Number of times: 3 MAX.

VPS P ackage peak temperature: 215 °C, Time: 40 seconds MAX. (200 °C MIN.),

Number of times: 3 MAX.

Wave soldering

Caution Do not use two or more soldering methods in combination.

Soldering bath temperature: 260 °C MAX., Time: 10 seconds MAX.,
Number of times: 1,
Preheating temperature: 120 °C MAX. (package surface temperature)

.

“Semiconductor Device Mounting

Conditions

IR35-00-3

VP15-00-3

WS60-00-1

18

Data Sheet G13690EJ3V0DS00

NOTES FOR BiCMOS DEVICES

1 PRECAUTION AGAINST ESD FOR SEMICONDUCTORS

Note:

Strong electric field, when exposed to a device, can cause destruction of the gate oxide and
ultimately degrade the device operation. Steps must be taken to stop generation of static electricity
as much as possible, and quickly dissipate it once, when it has occurred. Environmental control

must be adequate. When it is dry, humidifier should be used. It is recommended to avoid using
insulators that easily build static electricity. Semiconductor devices must be stored and transported
in an anti-static container, static shielding bag or conductive material. All test and measurement
tools including work bench and floor should be grounded. The operator should be grounded using
wrist strap. Semiconductor devices must not be touched with bare hands. Similar precautions need
to be taken for PW boards with semiconductor devices on it.

2 HANDLING OF UNUSED INPUT PINS

Note:

No connection for device inputs can be cause of malfunction. If no connection is provided to the
input pins, it is possible that an internal input level may be generated due to noise, etc., hence
causing malfunction. Input levels of devices must be fixed high or low by using a pull-up or pull-

DD

down circuitry. Each unused pin should be connected to V
considered to have a possibility of being an output pin. All handling related to the unused pins must
be judged device by device and related specifications governing the devices.

or GND with a resistor, if it is

µ

µ

PC1933

µ µ

3 STATUS BEFORE INITIALIZATION OF BiCMOS DEVICES

Note:

Power-on does not necessarily define initial status of device. Production process of BiCMOS does
not define the initial operation status of the device. Immediately after the power source is turned
ON, the devices with reset function have not yet been initialized. Hence, power-on does not
guarantee out-pin levels, I/O settings or contents of registers. Device is not initialized until the reset
signal is received. Reset operation must be executed immediately after power-on for devices
having reset function.

Data Sheet G13690EJ3V0DS00

19

µ

µ

PC1933

µ µ

[MEMO]

• The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.

• No part of this document may be copied or reproduced in any form or by any means without the prior written
consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may appear in
this document.

• NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual property
rights of third parties by or arising from use of a device described herein or any other liability arising from use
of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other
intellectual property rights of NEC Corporation or others.

• Descriptions of circuits, software, and other related information in this document are provided for illustrative
purposes in semiconductor product operation and application examples. The incorporation of these circuits,
software, and information in the design of the customer's equipment shall be done under the full responsibility
of the customer. NEC Corporation assumes no responsibility for any losses incurred by the customer or third
parties arising from the use of these circuits, software, and information.

• While NEC Corporation has been making continuous effort to enhance the reliability of its semiconductor devices,
the possibility of defects cannot be eliminated entirely. To minimize risks of damage or injury to persons or
property arising from a defect in an NEC semiconductor device, customers must incorporate sufficient safety
measures in its design, such as redundancy, fire-containment, and anti-failure features.

• NEC devices are classified into the following three quality grades:
"Standard", "Special", and "Specific". The Specific quality grade applies only to devices developed based on a
customer designated "quality assurance program" for a specific application. The recommended applications of
a device depend on its quality grade, as indicated below. Customers must check the quality grade of each device
before using it in a particular application.
Standard: Computers, office equipment, communications equipment, test and measurement equipment,
audio and visual equipment, home electronic appliances, machine tools, personal electronic
equipment and industrial robots
Special: Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster
systems, anti-crime systems, safety equipment and medical equipment (not specifically designed
for life support)
Specific: Aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life
support systems or medical equipment for life support, etc.
The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data Books.
If customers intend to use NEC devices for applications other than those specified for Standard quality grade,
they should contact an NEC sales representative in advance.

M7 98. 8