ICM7361T_技术文档

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

with guaranteed monotonic behavior. These DACs are

available in both a tiny 6-pin SOT-23 package and an 8-

pin MSOP package. They include a 1.25V reference for

ease of use and flexibility. The reference output is

available on a separate pin, in the 8-pin package version,

and can be used to drive external loads. The operating

supply range is 2.7V to 5.5V.

FEATURES

•

12/10/8-Bit Monotonic DACs in 6 lead SOT-23

Package

•

Wide Output Voltage Swing

Micro-Power

On Board 1.25V Reference

Serial Interface with three-wire SPI/QSPI and

Microwire Interface Compatible

8µs Full-Scale Settling Time

The input interface is an easy to use three-wire SPI/QSPI

compatible interface. The DAC has a double buffered

digitalkinput.

•

APPLICATIONS

•

Battery-Powered Applications

Industrial Process Control

Digital Gain and Offset Adjustment

OVERVIEW

The ICM7361, ICM7341 and ICM7321 are 12-Bit, 10-Bit

and 8-Bit wide output voltage swing DACs respectively,

BLOCK DIAGRAM

V_DD

ICM 7361/7341/7321

REFOUT

Reference

(MSOP-8

Package Only)

Input and

DAC Latch

12/10/8 -Bit

x2

V_OUT

DAC

Input Control Logic, Registers and Latches

SDI

Power-On-

Reset

SCK

CS

GND

PACKAGE

SOT-23

8-Pin MSOP

1

2

3

6

5

4

V_OUT

CS

1

2

3

4

8

7

6

5

V_DD

REFOUT

NC

GND

SDI

SCK

CS

GND

V_DD

SCK

SDI

V_OUT

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

1

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

PIN DESCRIPTION (MSOP-8 Package)

Pin No

Symbol

Description

1

2

3

4

V_DD

Supply Voltage

Reference Output (1.25V)

No Connect

REFOUT

NC

V_OUT

DAC Output

5

6

CS

SCK

Chip Select (TTL or CMOS)

Serial Clock Input (TTL or CMOS)

7

8

SDI

Serial Data Input (TTL or CMOS)

Ground

GND

PIN DESCRIPTION (SOT-23 Package)

Pin No

Symbol

Description

1

2

3

V_OUT

DAC Output

Ground

GND

V_DD

Supply Voltage

4

5

SDI

Serial Data Input (TTL or CMOS)

Serial Clock Input (TTL or CMOS)

SCK

6

CS

Chip Select (TTL or CMOS)

ABSOLUTE MAXIMUM RATING

Symbol

Parameter

Value

-0.3 to 7.0

Unit

V_DD

Supply Voltage

V

I_IN

Input Current

+/- 25.0

mA

V

V_{IN_}

V_{IN_REF}

T_STG

T_SOL

Digital Input Voltage (SCK, SDI, CS)

Reference Input Voltage

Storage Temperature

Soldering Temperature

-0.3 to 7.0

-65 to +150

300

V

^oC

Note: Stress greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress

rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this

specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

2

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

ORDERING INFORMATION

Part

Temperature Range

Package

ICM7361M

ICM7341M

ICM7321M

-40 ^oC to 85 ^oC

8-Pin MSOP

ORDERING INFORMATION

Part

Temperature Range

Package

ICM7361T

ICM7341T

ICM7321T

-40 ^oC to 85 ^oC

SOT-23

DC ELECTRICAL CHARACTERISTICS

(V_DD= 2.7V to 5.5V ; V_OUTunloaded; all specifications T_MINtoT_MAXunless otherwise noted)

Symbol

Parameter

Test Conditions

Min

Typ

Max

Unit

DC PERFORMANCE

ICM7361

N

DNL

INL

Resolution

Differential Nonlinearity

Integral Nonlinearity

12

Bits

LSB

(Notes 1 & 3)

0.4

4.0

+1.0

+12.0

ICM7341

N

Resolution

10

8

Bits

LSB

DNL

INL

Differential Nonlinearity

Integral Nonlinearity

(Notes 1 & 3)

0.1

1.0

+1.0

+3.0

ICM7321

N

Resolution

Bits

LSB

DNL

INL

Differential Nonlinearity

Integral Nonlinearity

(Notes 1 & 3)

0.05

0.25

+1.0

+0.75

GE

OE

Gain Error

Offset Error

+0.5

+25

% of FS

mV

POWER REQUIREMENTS

V_DD

I_DD

Supply Voltage

Supply Current

2.7

5.5

0.5

V

mA

(Note 4)

0.2

Symbol

Parameter

Test Conditions

Min

Typ

Max

Unit

OUTPUT CHARACTERISTICS

Output Voltage Range

(Note 3)

0

V_DD

V

VO_SC

R_OUT

Short Circuit Current

Amp Output Impedance

60

1.0

100

150

5.0

200

mA

Ω

At Mid-scale (Note 2)

At 0-scale (Note 2)

Ω

Output Line Regulation

V_DD=2.7 to 5.5 V

0.4

3.0

mV/V

LOGIC INPUTS

V_IH

V_IL

Digital Input High

Digital Input Low

Digital Input Leakage

(Note 2)

2.4

V

0.8

5

µΑ

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

3

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

REFERENCE

V_REFOUT

Reference Output

Reference Output Line

Regulation

1.2

1.25

0.8

1.3

4.0

V

mV/V

V_DD=2.7 to 5.5 V

AC ELECTRICAL CHARACTERISTICS

(V_DD= 2.7V to 5.5V; V_OUTunloaded; all specifications T_MINtoT_MAXunless otherwise noted)

Symbol Parameter Test Conditions Min

Typ

Max

Unit

SR

Slew Rate

2

8

V/µs

Settling Time

Full-scale settling

µs

Mid-scale Transition Glitch

Energy

40

nV-S

Note 1: Linearity is defined from code 64 to 4095 (ICM7361)

Linearity is defined from code 16 to 1023 (ICM7341)

Linearity is defined from code 4 to 255 (ICM7321)

Note 2: Guaranteed by design; not tested in production

Note 3: See Applications Information

Note 4: All digital inputs are either at GND or V_DD

TIMING CHARACTERISTICS

(V_DD= 2.7V to 5.5V; all specifications T_MINtoT_MAXunless otherwise noted)

Symbol

Parameter

Test Conditions

Min

30

10

Typ

Max

Unit

t₁

t₂

t₃

SCK Cycle Time

Data Setup Time

Data Hold Time

(Note 2)

ns

t₄

SCK Falling edge to CS

Rising Edge

(Note 2)

0

ns

t₅

CS Falling Edge to SCK

Rising Edge

15

(Note 2)

t₆

CS Pulse Width

20

ns

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

4

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

t₁

SCK

t₃

t₂

SDI

CS

C3

C2

MSB

t₅

Input Word for DAC N

t₄

t₆

Figure 1: Serial Interface Timing Diagram

CONTENTS OF INPUT SHIFT REGISTER

ICM7361 (12-Bit DAC)

MSB

LSB

D0

C3

C2

C1

C0

D11

D10

D9

D8

D7

D6

D5

D4

D3

D1

X

D2

D0

X

D1

Figure 2: Contents of ICM7361 Input Shift Register

ICM7341 (10-Bit DAC)

MSB

LSB

X

C3

C2

C1

C0

D9

D8

D7

D6

D5

D4

D3

D2

X

Figure 3: Contents of ICM7341 Input Shift Register

ICM7321 (8-Bit DAC)

MSB

LSB

X

C3

C2

C1

C0

D7

D6

D5

D4

D3

D2

D1

D0

X

Figure 4: Contents of ICM7321 Input Shift Register

C3

C2

C1

C0

DATA

FUNCTION

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

Data

X

Load Input Latch

Update DAC

Load Input Latch and Update DAC

No Operation

Table 1: Serial Interface Control Command

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

5

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

then decoded and the DAC is updated or loaded

depending on the control word (see Table 1).

DETAILED DESCRIPTION

The ICM7361 is

a 12-bit voltage output DAC. The

ICM7341 is the 10-bit version of this family and the

ICM7321 is the 8-bit version.

The DAC has a double-buffered input with an input latch

and a DAC latch. The DAC output will swing to its new

value when data is loaded into the DAC latch. The user

has three options: loading only the input latch, updating

the DAC with data previously loaded into the input latch or

loading the input latch and updating the DAC at the same

time with a new code.

This family of DACs has guaranteed monotonic behavior.

There is a 1.25V onboard reference and an operating

supply range of 2.7V to 5.5V.

Reference Output

There is an internal bandgap reference of 1.25V on these

parts and there is a gain of two in the output amplifiers

which means they swing from ground at code 0 to 2.5V at

full-scale :

Power-On Reset

There is a power-on reset on board that will clear the

contents of all the latches to all 0s on power-up and the

DAC voltage output will go to ground.

Vout = 2 x (1.25 xD)/2ⁿ

Where D=digital input (decimal) and n= number of bits, i.e.

12 for ICM7361, 10 for ICM7341 and 8 for ICM7321.

The reference output is nominally 1.25V and is brought out

to a separate pin, REFOUT (8-pin MSOP package only)

and can be used to drive external loads. However, it is still

internally connected to the DAC reference input. The

outputs will nominally swing from 0 to 2.5V.

Output Amplifier

The DAC has an output amplifier with a wide output

voltage swing. The actual swing of the output amplifier will

be limited by offset error and gain error. See the

Applications Information Section for

discussion.

a more detailed

The amplifier is configured in a gain of 2 with internal gain

resistors of about 50 kΩ. The output swing will be from 0V

to 2.5V at full-scale.

The output amplifier can drive a load of 2.0 kΩ to V_DDor

GND in parallel with a 500 pF load capacitance.

The output amplifier has a full-scale typical settling time of

8 µs and it dissipates about 100 µA with a 3V supply

voltage.

Serial Interface and Input Logic

This DAC family uses a standard 3-wire connection

compatible with SPI/QSPI interfaces. Data is loaded in 16-

bit words which consist of 4 address and control bits

(MSBs) followed by 12 bits of data (see table 1). The

ICM7341 has the last two LSBs as don’t cares and the

ICM7321 has the last 4 LSBs as don’t cares. The DAC is

double buffered with an input latch and a DAC latch.

All the digital inputs are CMOS/TTL compatible. The

current dissipation of the device however, will be higher

when the inputs are driven at TTL levels.

Data is clocked in on the rising edge of SCK which has a

Schmitt trigger internally to allow for noise immunity on the

SCK pin. This specially eases the use for opto-coupled

interfaces.

The CS pin must be low when data is being clocked into

the part. After the 16^thclock pulse the CS pin must be

pulled high (level-triggered) for the data to be transferred

to an input bank of latches. The CS pin also disables the

SCK pin internally when pulled high and the SCK pin must

be low before the CS pin is pulled back low. As the CS pin

is pulled high the shift register contents are transferred to

a bank of 16 latches. The 4 bit control word (C3~C0) is

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

6

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

input is loaded into the DAC the output will eventually rise

above ground. This is why the linearity is specified for a

starting code greater than zero.

APPLICATIONS INFORMATION

Power

Considerations

Supply

Bypassing

and

Layout

Figure 6 illustrates how a gain error or positive offset error

will affect the output when it is close to V_DD. A positive gain

error or positive offset will cause the output to be limited to

the positive supply voltage resulting in a dead-band of

codes close to full-scale.

As in any precision circuit, careful consideration has to be

given to layout of the supply and ground. The return path

from the GND to the supply ground should be short with

low impedance. Using a ground plane would be ideal. The

supply should have some bypassing on it. A 10 µF

tantalum capacitor in parallel with a 0.1 µF ceramic with a

low ESR can be used. Ideally these would be placed as

close as possible to the device. Avoid crossing digital and

analog signals, specially the reference, or running them

close to each other.

Output Swing Limitations

The ideal rail-to-rail DAC would swing from GND to V_DD

however, offset and gain error limit this ability. Figure 5

illustrates how a negative offset error will affect the output.

The output will limit close to ground since this is single

supply part, resulting in a dead-band area. As a larger

DEADBAND

NEGATIVE

OFFSET

Figure 5: Effect of Negative Offset

OFFSET AND

GAIN ERROR

V_DD

DEADBAND

POSITIVE

OFFSET

Figure 6: Effect of Gain Error and Positive Offset

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

7

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

PACKAGE INFORMATION

8-Pin MSOP Package

SOT-23 Package

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

8

IC

mic

ICM7361/7341/7321

IC MICROSYSTEMS

SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS

ORDERING INFORMATION

ICM73X1 P G

G = RoHS Compliant Lead-Free package.

Blank = Standard package. Non lead-free.

Device

6 - ICM7361

4 - ICM7341

2 - ICM7321

Package

M = 8-Lead MSOP

S = 6-Lead SOT-23

Rev. A8

ICmic reserves the right to change the specifications without prior notice.

9


型号：	ICM7361T
厂家：	IC MICROSYSTEMS
描述：	SINGLE 12/10/8-BIT VOLTAGE-OUTPUT DACS 一个12 /10/ 8位电压输出DAC 输出元件
文件：	总9页 (文件大小：167K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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