Datasheet LC7972VB, LC7972VA Datasheet (SANYO)

Overview

The LC7972VA and LC7972VB are dual
inverting/noninverting operational amplifier ICs that are
fabricated in a CMOS process. These ICs provide a
programmable offset correction function and a power
saving function for use when the operational amplifier is
unused, both of which can be controlled from a
microprocessor interface.

Features

• High input impedance provided by fabrication in a
CMOS process.

• Low power provided by fabrication in a CMOS process.

• One of two types of operational amplifier can be
selected: inverting (operational amplifier 1) or
noninverting (operational amplifier 2)

• Operating supply voltage: 4.9 to 5.2 V

• Package: SSOP20

• Operating temperature: Ta = –30 to +70°C

• The following modes are supported. These are selected
via port level settings.

Package Dimensions

unit: mm

3179A-SSOP20

CMOS LSI

Ordering number : EN5682

73097HA(OT) No. 5682-1/4

SANYO: SSOP20

[LC7972VA, VB]

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN

CMOS Operational Amplifier with Programmable

Offset Correction Function

LC7972VA, 7972VB

Port Level Function

OP1ON

L Operational amplifier 1: Operation stopped (low-power mode)
H Operational amplifier 1: Normal operation (OP2ON must be low in this mode.)

OP2ON

L Operational amplifier 2: Operation stopped (low-power mode)
H Operational amplifier 2: Normal operation (OP1ON must be low in this mode.)

OFST1

L Operational amplifier 1: Offset mode (inverting input = V

SS

)

H Operational amplifier 1: Operating mode (inverting input = normal input)

OFST2

L Operational amplifier 2: Offset mode (noninverting input = V

SS

)

H Operational amplifier 2: Operating mode (noninverting input = normal input)

CLKC L Operational amplifier power supply clock: Internal clock

This catalog provides information as of July, 1997. Specifications and information herein are subject to change
without notice.

■ No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace
equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of
which may directly or indirectly cause injury, death or property loss.

■ Anyone purchasing any products described or contained herein for an above-mentioned use shall:
➀ Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and

distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all
damages, cost and expenses associated with such use:

➁ Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on

SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.

■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied
regarding its use or any infringements of intellectual property rights or other rights of third parties.

Pin Assignment

No. 5682-2/4

LC7972VA, 7972VB

Pin Functions

Pin

Function

No. Symbol

1 DV

DD

Digital system power supply. Normally connected to +5 V.
2 EXT Must be tied low.
3 CLKC Must be tied low.
4 OP2ON Operational amplifier 2 operation control
5 OFST2 Operational amplifier 2 mode control
6 OP1ON Operational amplifier 1 operation control
7 OFST1 Operational amplifier 1 mode control
8 TGO Operational amplifier 1 VSS/small voltage output
9 OP1I Operational amplifier 1 input

10 OP1O Operational amplifier 1 output
11 OP2O Operational amplifier 2 output
12 OP2I Operational amplifier 2 input
13 TGI Small voltage input common to operational amplifiers 1 and 2
14 AV

SS

M Operational amplifier power supply minus voltage generation

15 AV

DD

Analog system power supply. Normally connected to +5 V.

16 AV

SS

P Operational amplifier power supply external Zener diode connection

17 AV

SS

Analog system ground. Must be connected to 0 V.

18 CUP2 Operational amplifier power supply external capacitor connection 2
19 CUP1 Operational amplifier power supply external capacitor connection 1
20 DV

SS

Digital system ground. Must be connected to 0 V.

System Block Diagram and Sample Application

A circuit that amplifies very small voltages around the VSSlevel can be constructed by adding the peripheral circuits
shown in the figure below.

No. 5682-3/4

LC7972VA, 7972VB

A/D converter inputs

Port outputs

Microcontroller

Small-voltage input

Step-down

voltage

converter circuit

No. 5682-4/4

LC7972VA, 7972VB

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

DD

max V

DD

–0.3 to +7.0 V

Output voltage V

O

OP1O, OP2O, TGO –0.3 to VDD+0.3 V

V

I

1

OP1ON, OFST1, OP2ON, OFST2, EXT, CLKC, CUP2,

–0.3 to VDD+0.3 V

Input voltage

CUP1, AV

SS

P, OP1I, OP2I, TGI

V

I

2 AVSSM –3 to +0.3 V

Peak output current I

OP

OP1O, OP2O, TGO –1 to +1 mA

Average output current I

OA

OP1O, OP2O, TGO : The current per pin –1 to +1 mA
Allowable power dissipation Pd max SSOP20 : Ta = –30 to +70°C 100 mW
Operating temperature Topr –30 to +70 °C
Storage temperature Tstg –55 to +125 °C

Specifications

Absolute Maximum Ratings at Ta = 25°C, VSS= 0 V

Parameter Symbol Conditions

Ratings

Unit

min typ max

Supply voltage V

DDVDD

4.9 5.2 V

Input high-level voltage V

IH

OP1ON, OFST1, OP2ON, OFST2 0.7 V

DD

V

DD

V

Input low-level voltage

V

IL

1 OP1ON, OFST1, OP2ON, OFST2, CLKC V

SS

0.3 V

DD

V

V

IL

2 EXT V

SS

0.3 V

DD

V

Common-mode input voltage V

IC

0 4.2 V

Voltage drop D

V

AVSSM:

Zener diode = 5.1 V (X rank specified)

–0.2 V

Allowable Operating Ranges at Ta = –30 to +70°C, VSS= 0 V, VDD= 4.9 to 5.2 V, unless otherwise specified

Parameter Symbol Conditions

Ratings

Unit

min typ max

Input high-level current

I

IH

1 OP1ON, OFST1, OP2ON, OFST2 : VIN= V

DD

1.0 µA

I

IH

2 TGI: VIN= VDD, with the built-in TG off. 1.0 µA

I

IL

1

OP1ON, OFST1, OP2ON, OFST2, EXT,

–1.0 µA

Input low-level current

CLKC : V

IN

= V

SS

IIL2 TGI: VIN= VSS, with the built-in TG off. –1.0 µA

Output high-level voltage V

OH

OP1O, OP2O : IOH= –3 µA V

DD

– 0.5 V

Output low-level voltage V

OL

OP1O, OP2O : IOL= 3 µA 0.5 V
Operational amplifier 1 gain-related resistance Rtg + 2Rs TGO, TGI 500 700 900 Ω
Operational amplifier 1 gain-related resistance

|Rx–Ry|

TGO, TGI: Offset mode: Rx = Rtg + 2Rs

80 Ω

difference Operating mode: Ry = Rtg + 2Rs
Current drain

Operating I

DDOP

VDD; Using the internal clock, with the

700 900 µA

operational amplifier 1 circuit operating.
Standby I

DDST

VDD; Both operational amplifiers 1 and 2

0.05 10 µA

stopped.

Electrical Characteristics at Ta = –30 to +70°C, VSS= 0 V, VDD= 4.9 to 5.2 V, unless otherwise specified

Parameter Symbol Conditions

Ratings

Unit

min typ max

Input offset voltage V

IO

OP1I, OP2I :LC7972VA 5 10.5 mV

LC7972VB 5 15 mV

Supply voltage rejection ratio P

SRR

1 kHz 60 dB
Common-mode rejection ratio C

MRR

60 dB

Open-loop voltage gain A

O

80 dB

0-dB bandwidth f

T

90 kHz

Maximum output voltage V

O

OP1O, OP2O : RL≥ 100 kΩ V

DD

– 0.5 V

Current drain I

CC

For the operational amplifier 1 circuit 100 µA
Settling time T

SET

OP1O, OP2O 900 µs

Operational Amplifier Characteristics

at Ta = 25°C ±2°C, VSS= 0 V, VDD= 4.9 to 5.2 V, unless otherwise specified