ES51927_10_技术文档

ES51927

6000 Counts Smart DMM

Features

z

6000 counts LCD display

General description

3V DC power supply

Conversion rate: 3 times/s (voltage mode)

Full automatic measurement:

*Voltage/Current: AC/DC auto scanning

& auto range: 6.000V~1000V

*Resistance/Diode/Capacitance(RDC scan)

(Taiwan patent no.: 326361)

Auto scanning & auto range:

Resistance: 600.0Ω~6.000MΩ

Capacitance: 6.000nF~600.0uF

(Taiwan patent no.: 323347,453443)

Push functions

ES51927 is an integrated ADC with 6000 counts

LCD display driver. It could support fully

automatic DMM function measurement. In

voltage or current mode, the AC or DC signals

auto scanning. In R/D/C (passive component)

mode,

resistance

(including

continuity),

capacitance or diode measurements are allowed

by fully automatic detection. A single key and

simple switch could select all measurements.

Expensive and bulky mechanical range switches

are not required. A non-contact electric field

detector (EF mode) is built-in for ac voltage

measurement also. Other features including

range control, data hold, VAHz and back light

function are available. For power saving, an auto

power off & re-power on scheme are built-in. A

sleep output is the indication of entering auto

power off mode.

z

Function selection by single key

Range change function

Hold function

VAHZ function

Back light function

z

Support non-contact voltage detection

High voltage (> 30V) indication of LCD

display for voltage measurement

Built-in HCF(high crest factor detection)

function in AC mode

z

(Taiwan patent no.: 234661)

OL level selection (600V/1000V/1500V)

Band-gap reference voltage output

Auto power off (3min. or 10min.) &

re-power on

z

Sleep output indication

On-chip buzzer driver

Low battery detection

Application

z

Smart digital multi-meter

z

Smart clamp meter

Ver 2.9

1

10/06/25

ES51927

6000 Counts Smart DMM

Pin Assignment

50

45

40

35

30

NC

SEG11

SEG10

NC

80

SEG09

SEG08

SEG07

SEG06

SEG05

SEG04

SEG03

SEG02

SEG01

OSC2

OSC1

BKSEL

CESEL

C+

ACEN

BUZOUT

APOSEL

BUZIN

SLEEP

R1K

R9K-

CA+

CA-

NC

VR1

VA-

VA+

Cyrustek.

com.tw

85

90

ES51927

ADP

SGND

VR

VRH

NC

C-

V-

V+

95

V+

OHMC1

OHMC2

DGND

AGND

100

Pin Description

Pin No

Symbol

AGND

LBAT

Type

P

I

Description

1

2

Analog ground.

Low battery configuration. If 3V battery is used, connect it to DGND.

The default low-battery threshold voltage is –2.3V. If 9V battery is

used, the low battery enunciator is displayed when the voltage of

this pin is less than VRH (-1.2V)

3

4

5

6

7

8

CREF+

CREF-

CINT

CAZ

BUFF

RAZ

I/O Positive connection for reference capacitor.

I/O Negative connection for reference capacitor.

O

I

Integrator output. Connect to integral capacitor

Auto-zero capacitor connection.

O

Buffer output pin. Connect to integral resistor

Buffer output pin in high-speed mode. Connect to high-speed integral

resistor.

9

IVSH

I

High current measurement input.

Ver 2.9

2

10/06/25

ES51927

6000 Counts Smart DMM

10

11

12

13

14

15

16

17

18

19

20

IVSL

OVX

OVH

OVSG

OR1

VR5

VR4

VR3

VR2

I

Low current measurement input

Input high voltage for resistance/capacitor measurement

Output connection for resistance/capacitor measurement

Sense low voltage for resistance measurement

Reference resistor connection for 600.0Ω range

Voltage measurement ÷10000 attenuated (1000V)

Voltage measurement ÷1000 attenuated (600.0V)

Voltage measurement ÷100 attenuated (60.00V)

Voltage measurement ÷10 attenuated (6.000V)

I

O

TEST5

ACVL

I/O Test pin

I

DC signal low input in ACV/ACA mode. Connect to negative output of

external AC to DC converter.

21

ACVH

I

DC signal high input in ACV/ACA mode. Connect to positive output of

external AC to DC converter.

22

23

24

25

26

27

28

29

30

31

32

33

ADI

ADO

I

O

-

O

I

Negative input of internal AC to DC OP Amp.

Output of internal AC to DC OP Amp.

Filter capacitor connection for resistance mode

OHMC4

OHMC3

OHMC2

OHMC1

NC

VRH

VR

SGND

ADP

VA+

Output of band-gap voltage reference. Typically –1.2V

Reference input voltage connection. Typically –400mV

Signal Ground.

Measurement input in ADP mode

For ADP mode. De-integrating voltage positive input. The input should

be higher than VA-.

I

34

VA-

I

For ADP mode. De-integrating voltage negative input. The input should be

lower than VA+.

35

36

VR1

NC

I

-

Measurement input.

37

38

CA-

CA+

I/O Negative auto-zero capacitor connection for capacitor measurement

I/O Positive auto-zero capacitor connection for capacitor measurement

39

40

41

42

43

44

45

46 – 50

51

R9K

R1K

O

I

Connect to a precise 9KΩ resister for capacitor measurement.

Connect to a precise 1KΩ resister for capacitor measurement.

Sleep mode indicator, asserts low in SLEEP mode. Normal V+ output.

Pull to V- to enable the BUZOUT.

Auto power off idle time selection.

Outputs a 2KHz audio frequency signal for driving piezoelectric buzzer

Output to V- when AC mode inactive and output to V+ in AC mode.

SLEEP

BUZIN

APOSEL

BUZOUT

ACEN

NC

I

O

-

BKOUT

O

If BKLIT function is enabled, this pin will change from –3V to +3V

for 60 sec, once press BKLIT pin again within 60 sec, this pin will change

back to –3V.

52

ANNUNC

O

Square wave output at the backplane frequency, synchronized to BP1.

ANNUNC can be used to control display annunciator. Connect a LCD

segment to ANNUNC to turn it on; connect an LCD segment to its back

plane to turn it off.

53

54

55

56

57

58

59

60

BP4

BP3

BP2

O

I

-

I

LCD backplane 4

LCD backplane 3

LCD backplane 2

LCD backplane 1

Pull-low to enable non-contact AC voltage detection

Back light function. Pulse low to set BKOUT pin output.

BP1

EFEN

BKLIT

NC

RANGE

Pulse to V- to enable manual mode and manual range selection.

Ver 2.9

3

10/06/25

ES51927

6000 Counts Smart DMM

61

62

VAHz

SEL

I

Pulse to V- to enable VAHz mode.

Pulse to V- to select target measurement

63

64

HOLD

FC1

I

Pulse to V- to enable HOLD function.

Switch 1 for function selection.

65

FC2

I

Switch 2 for function selection.

66

FC3

I

Switch 3 for function selection.

67

68

69

70

FUA

FA

AON

VON

I

O

-

O

I

O

Switch 1 for current measurement selection.

Switch 2 for current measurement selection.

Pull to high to sense current measurement priority in auto scan mode

Pull to high to sense voltage measurement priority in auto scan mode

Switch for clamp meter application function

LCD segment line 10 – 15

71

CLAMP

SEG15 – 10

NC

SEG09 - 01

OSC2

OSC1

72 – 77

78 – 79

80 – 88

89

LCD segment line 01 – 09

Crystal oscillator input connection

Crystal oscillator output connection

90

When pulled to V-, an auto back light configuration is allowed.

Configure a low level applied to BKLIT larger than 1 second, the

BKOUT will be active.

91

BKSEL

I

If BKLIT is back to high level, the BKOUT would be inactive.

92

93

94

95

96

97

98

99

100

CESEL

C+

C-

V-

V+

DGND

AGND

I

OL selection feature control pin.

O

P

Positive capacitor connection for on-chip DC-DC converter.

Negative capacitor connection for on-chip DC-DC converter.

Negative supply voltage. Connecting to battery negative terminal.

P

P/O Output of on-chip DC-DC converter.

G

Digital ground.

Analog ground.

Absolute Maximum Ratings

Characteristic

Supply Voltage (V- to AGND)

Analog Input Voltage

V+

Rating

-4V

V- -0.6 to V+ +0.6

V+ ≥ (AGND/DGND+0.5V)

AGND/DGND

AGND/DGND ≥ (V- -0.5V)

V- -0.6 to DGND +0.6

500mW

Digital Input

Power Dissipation. Flat Package

Operating Temperature

Storage Temperature

0℃ to 70℃

-25℃ to 125℃

Ver 2.9

4

10/06/25

ES51927

6000 Counts Smart DMM

Electrical Characteristics

TA=25℃, V- = -3V

Parameter

Power supply

Operating supply current

In Scan AC/DC mode

Symbol

V-

I_DDNormal operation

I_SSIn sleep mode

REV 10MΩ input resistor

Test Condition

Min.

-3.5

—

Typ.

-3.0

2.5

0.6

—

Max

-2.5

—

Units

V

mA

2.5

µA

—

Voltage roll-over error

±0.1 %F.S¹

—

Best case straight

—

Voltage nonlinearity

NLV

line

±0.1

%F.S

Input Leakage

-10

-2.4

-000

1

-2.3

000

10

-2.2

+000 counts

PA

V

Low battery flag voltage

Zero input reading

Peak to peak backplane

drive voltage

V- to AGND

10MΩ input resistor

-3.5V≤ V ≤-2.2V

3.0

3.15

1

3.3

V

Counter time base period

f_OSC= 4MHZ

—

sec

Reference voltage and open circuit

voltage for 600Ω measurement

100KΩ resistor

V_REFbetween VRH and

AGND

-1.33

-0.86

-1.23

-0.78

-1.13

-0.70

V

Open circuit voltage for Ω

measurement (except 600Ω)

Ω and Continuity

Mode

Between V- pin and

HOLD, RANGE,

SEL,FC1-3,FUA,

FA, VON, AON,

CLAMP, BKLIT

Internal pull-high to 0V

current

—

1.2

µA

HZ

AC frequency response at 6.000V

Range

±1%

±5%

40-400

400-2000

—

10

—

AC input response for scan mode

50000

Hz

AC/DC voltage scan mode

sensitivity@1kHz

AC/DC current scan mode

sensitivity@1kHz

VR1(10MΩ input

impedance)

ADP, IVSL and IVSH

300

8

450

10

600

12

mV

pF

Parasitic capacitance

allowed in 6.000MΩ

range

—

RDC scan mode RES sensitivity

200

RDC scan mode DIODE sensitivity

RDC scan mode CAP sensitivity

Reference voltage temperature

coefficient

Forward voltage

0.8

—

V

pF

—

400

100KΩ resister

Between VRH

—

ppm/℃

TC_RF

50

0℃<TA<70℃

—

-1.5

-5

-2.0

1.5

5

2.0

%F.S

counts

%F.S

6nF – 6.0µF

Capacitance measurement

accuracy

60µF ~ 60mF

—

-5

5

counts

Note:

1.Full Scale

Ver 2.9

5

10/06/25

ES51927

6000 Counts Smart DMM

Functional Description

1. Operation Modes

1.1 Voltage Measurement

A re-configurable voltage divider automatically provides a suitable range in

voltage measurement mode. The following table summarizes the full-scale ranges

in each configuration.

Configuration

VR1

Full Scale Range

600.0mV*

6.000V**

60.00V

Divider Ratio

1

Resister Connection

VR1 (10MΩ)

VR2 (1.111MΩ)

VR3 (101KΩ)

VR4 (10KΩ)

VR2

VR3

VR4

VR5

1/10

1/100

1/1000

1/10000

600.0V

1000V***

VR5 (1KΩ)

Note:

* Exists in manual mode only by RANGE key control

**This range is the default range for auto range & auto scan mode

*** Depends on CESEL selection

1.1.1 OL selection

ES51927 has a OL display selection feature archived by configuring a CESEL

pin. If pin CESEL is connected to V-, ES51927 will have a 600.0V overflow

level in DC and AC 600.0V ranges. And the 1000V range will not occur anymore.

If pin CESEL is connected to DGND, the ES51927 will have a 1010V overflow

level in DCV mode and have a 1010V overflow level in ACV mode also. When

CE is floating, a 1500V overflow level in DCV mode but ACV is still 1010V

overflow level. The meter will Show OL when the measuring signal reaches the

overflow level with beeper warning. The configuration of CESEL is listed below.

CESEL

V-

DGND

Floating

DCV

600.0V

1010V

1500V

ACV

600.0V

1010V

Ver 2.9

6

10/06/25

ES51927

6000 Counts Smart DMM

1.1.2 HCF detection

ES51927 provides detection of high-crest-factor (HCF) signal in ACV auto range

mode. ES51927 senses the signal and determines it as HCF if the Vpp is large

enough. Once the signal is determined as HCF, ES51927 will jump up one

measuring range regardless of current measurement value. It takes 60ms to jump

one range up. The jumping up process will continue until the maximum range is

reached. With HCF detection, a more accurate result could be obtained. For

example, when a input signal with Vpp=350V, Vrms=70V(CF=5) was applied,

traditional DMM might stay at 60V range but shows counts with the amount of

error up to 10% or even bigger. The error rises from limited input/output swing

at internal ADC. With HCF detection, DMM will stay at 600V range and exhibits

more accurate results.

1.1.3 EF mode

ES51927 supports a non-contact ac voltage measurement, which is called electric

field measurement also. The EF mode is selected by SEL key when EF_EN is

active. The ADC input is configured from ADP pin vs. SGND. When no or less

electric field is detected, the LCD shows “EF”. If the detector senses electric

field, the strength will be showed on LCD by “-“ not digits type. Level 1(weak)

is “-“ and the level 4(strong) is “----“. Additional beeper will be output from

BUZOUT pin. The buzzer frequency depends on the strength of electric field also.

The Faster beeper means the stronger electric field (ac voltage) is sensed.

Ver 2.9

7

10/06/25

ES51927

6000 Counts Smart DMM

1.2 Current Measurement

1.2.1 For multi-meter application

ES51927 has 2 automatic and 1 manual current measurement modes for

multi-meter. The following table summarizes the full-scale range of each mode.

When ES51927 operates in the current measurement modes for multi-meter, it

takes high input from pin IVSH or IVSL, low input from pin SGND and

reference voltage from pin VR.

Mode

Automatic1

Full Scale

600.0µA / 6000µA

Input Terminal

IVSL/IVSH V.S. SGND

Full scale

300.0mV

Automatic2 60.00mA / 600.0mA IVSL/IVSH V.S. SGND

Manual 60.00A IVSH V.S. SGND

1.2.2 For clamp meter application

ES51927 has 2 automatic and 4 manual current measurement modes for Clamp

meter. The following table summarizes the full-scale range of each mode. When

ES51927 operate in the automatic mode1&2, it takes high input from

IVSH/IVSL (higher range/lower range), low input from SGND and reference

voltage from VR. When ES51927 operate in the manual mode1~4, it takes high

input from ADP, low input from SGND and reference voltage from VA+ & VA-.

Mode

Automatic1

Automatic2

Manual1

Manual2

Manual3

Manual4

Full Scale

600.0A / 6000A

60.00A / 600.0A

6.000A

Input Terminal

IVSL/IVSH V.S. SGND

ADP V.S. SGND

Full scale

600.0mV

60.00A

600.0A

6000A

ADP V.S. SGND

Ver 2.9

8

10/06/25

ES51927

6000 Counts Smart DMM

1.3 Resistance Measurement

A re-configurable divider automatically provides a suitable full-scale range in

resistance measurement mode. The following table summarizes the full-scale

ranges and the reference resistors in each configuration.

Configuration

OR1

Full Scale Range

600.0Ω*

Relative Resistor

OR1

Equivalent value

100Ω

OR2

6.000KΩ

VR5

1KΩ

OR3

60.00KΩ

VR4

10KΩ

OR4

600.0KΩ

100KΩ

VR3∥VR1

OR5

OR6

6.000MΩ

60.00MΩ**

1MΩ

10MΩ

VR2∥VR1

VR1

Note: * When auto scan mode is set, continuity check is implemented in this range

** When auto scan mode is set, the 60.00MΩ range is omitted

1.3.1 Continuity check

Continuity check shares the same configuration with 600.0Ω manual resistance

measurement mode and has buzzer output to indicate continuity. The buzzer

generates 2KHz beep whenever the reading is less than 30Ω.

1.4 Diode Measurement

Diode measurement mode shares the same configuration with 6.000V manual

voltage measurement mode and has buzzer output to indicate continuity. The

buzzer generates a 2KHz sound whenever the reading is less than 30mV. If the

test circuit is open or the voltage drop between the two ports of the device (diode)

under test is larger than 2V, the LCD panel will show “OL”.

Ver 2.9

9

10/06/25

ES51927

6000 Counts Smart DMM

1.5 Capacitance Measurement

The following table summarizes the eight ranges of capacitance measurement

mode:

Configuration Full Scale Range

Relative Resistor

20kΩVR+100kΩ

101kΩ

C1

C2

C3

C4

C5

C6

C7

C8

6.000nF

60.00nF

600.0nF

6.000uF

60.00uF

600.0uF

6.000mF*

60.00mF**

10kΩ

R9K / R1K

Note: ^{* & **}The C7-C8 both range is not available for auto scan mode

In order to obtain an accurate reading, a capacitor must be discharged before

measurement begins. The chip has a built-in discharge mode to automatically

discharge the capacitor. In discharge mode, the LCD displays “dIS.C”

Discharging through the chip is quite slow. We recommend users to discharge the

capacitor with some other apparatus.

1.6 Auto power off mode (APO)

1.6.1 Idle Time selection

ES51927 has a default auto power off function. If the meter is idle for more than

the given Idle Time, the chip automatically turns the power off. The idle time to

trigger the auto power off function is determined by pin ‘APOSEL’. If pin

APOSEL is connected to V-, the Idle Time will be set to 3 minutes. If pin

APOSEL is connected to DGND or floating, the Idle Time will be set to 10

minutes. When APO happens, the state of the meter is saved. If the APO is

necessary to be cancelled, power on the ES51927 when any of the push key,

except for HOLD, is pressed down simultaneously.

1.6.2 Sleep output

Ver 2.9

10

10/06/25

ES51927

6000 Counts Smart DMM

The meter enters sleep mode after auto power-off or push SEL key to last for 2s.

The SLEEP pin asserts low (-3V) in the sleep mode, and asserts high (+3V, not 0V)

after re-power on.

1.6.3 Re-power on

After auto power-off is active, pushing any of the push function or changing the

measurement function can turn on the meter again. If the meter is re-powered on

by changing measurement function, the saved state is cleared. If the meter is

re-powered on by push functions, the chip restores the saved state and enters

HOLD mode. The LCD displays the saved value except for the auto scan mode.

Ver 2.9

11

10/06/25

ES51927

6000 Counts Smart DMM

2. Functional Modes Table

Measurement mode depends on the logic level of FC1, FC2, FC3, FUA, FA,

VON, AON and CLAMP.

FC1 FC2 FC3 FUA FA VON AON CLAMP

Functional Mode(pushing SEL key)

V_AUTOÆV_ACÆV_DCÆEF*ÆV_AUTOÆ…

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(uA)

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(mA)

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(A)

V_AUTOÆV_ACÆV_DCÆV_AUTOÆ…

I_AC(600.0A/6000A)

Input

VR1,ADP

IVSH/IVSL

IVSH

1

0

1

X

1

0

1

0

1

0

1

X

1

0

X

1

X

0

1

X

0

X

1

0

X

0

1

0

1

X

1

X

VR1

IVSH/IVSL

VR1

0

I_AC(60.00A/600.0A)

X

RDC_AUTOÆRÆDÆCÆRDC_AUTOÆ…

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(6.000A)

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(60.00A)

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(600.0A)

I_AUTOÆI_ACÆI_DCÆI_AUTOÆ…(6000A)

ADP

0

Note: * EF mode could be selected when EF_EN is active.

3. Push Function

All the enabled push functions will be reset when the measurement mode is

changed by external switch. Change measurement mode by SEL function will

reset enabled RANGE, HOLD, and VAHz functions. The following table lists the

available function versus every measurement mode.

SEL

O

RANGE

HOLD

X

VAHz

O

BKLIT

O

V_SCAN

V_AC

X

O

V_DC

O

EF

O

X

O

I_SCAN

O

X

O

I_AC

I_DC

RDC_SCAN

Resistance

Continuity

Diode

O

O*

X

O

X

O

X

O

X

O

X

Capacitance

O

X

O

Note: For ADP input, RANGE is not available

Ver 2.9

12

10/06/25

ES51927

6000 Counts Smart DMM

3.1 Select function

When power on or SEL key is pressed longer than one second, ES51927 will be

power-on reset to auto scan mode, which scanning mode is determined by

[FC1-FC3] function set. In auto scan mode, the ES51927 automatically selects

the appropriate measurement mode and range. Pushing the SEL key less than one

second could select the target measurement function. Pushing the key larger than

two seconds, the ES51927 will enter power down mode. If power down mode is

entered, only press SEL key to last for one second or apply the power to V-

terminal could re-power on the ES51927. The following figure shows the state

transition.

Push SEL key < 1s

V/A

AC mode

DC mode

EF* mode

ac/dc auto scan

measurement

Push SEL key > 1s

Power on reset

Push SEL key > 2s Æ enter power down mode

R/D/C

auto scan

Resistance

measurement

Continuity

measurement

Diode

measurement

Capacitance

measurement

Push SEL key < 1s

Note: * Available when EF_EN is active only

Ver 2.9

13

10/06/25

ES51927

6000 Counts Smart DMM

3.2 Range function

RANGE pin switches to and from automatic and manual mode, and while in

manual mode, changes the full-scale range. The following figure shows the state

transition.

1 push < 1 sec

Automatic

Mode

Manual

Mode

1 push > 1 sec

Range up

1 push < 1 sec

3.3 Hold and delay-hold function

The data hold mode makes the meter stop updating the LCD panel. This mode

can be nested in most of the special modes. In auto scanning mode, the HOLD

key is not available. Enabling hold function in automatic mode makes the meter

switch to manual mode. Hold function can be cancelled by changing the

measurement mode, pressing RANGE, or push HOLD again.

The delay-hold function is enabled when HOLD key is pressed larger than 2

seconds. When delay-hold function is entered successfully, the meter will stop to

update the LCD data after six seconds delayed. During the six seconds waiting,

the HOLD symbol on LCD panel will be blinking.

Push > 2s

Push < 2s

Normal mode

(Auto/Manual)

HOLD mode

(Manual)

6sec past

Delay State

Push > 2s

Push < 2s

(Auto/Manual)

Ver 2.9

14

10/06/25

ES51927

6000 Counts Smart DMM

3.4 VAHz function

When voltage or current measurement mode is selected, the VAHz funtion is

available. Push VAHz key to select this frequency measurement mode. The

frequency is measured by auto ranging. The maximum frequency range is

100kHz. The sensitivity of signal input is 10% full scale of voltage or current

mode typically.

Configuration

Range

FR1

FR2

FR3

6.000KHz

60.00KHz

100.0KHz

3.5 Back light function

When BKSEL is set to DGND or floating, push the BKLIT key to enable the back

light output driving ON/OFF. If the auto back light configuration is active, the

BKLIT becomes a control input for external light sensed circuit. Set to low for one

second to active the back light output driving. Set to high then the driving output is

inactive immediately.

BKSEL

DGND or floating

V-

Configuration

Normal back light function

Auto back light function

Ver 2.9

15

10/06/25

ES51927

6000 Counts Smart DMM

4. Miscellaneous

The conditions, which the meter turns on the buzzer, include:

(1) Changing measurement mode generates one beep.

(2) Pressing any of the push functions generates one beep, if the function is valid.

(3) Power on and re-power on generate one beep.

(4) Input overflow in voltage and current mode generates one beep every 0.3

seconds (or 3.33 beeps per second.)

(5) Continuity (diode) check generates a continuous 2KHz beep whenever the

measurement is less then 30Ω(30mV)

(6) Auto power off or power down by SEL key generates a 2KHz beeper that lasts

for 1.5 seconds.

The following figures show the output waveform from the BUZOUT pin.

0.5 mS

(a) Continuous 2KHz beep

0.15 sec

0.3 sec

(b) 3.33 beep/sec

Ver 2.9

16

10/06/25

ES51927

6000 Counts Smart DMM

4.1 LCD configuration

S14 S12

S1

S2 S3 S4 S5 S6

S7 S8 S9 S10 S11

S15

S13

APO

MANU

SCAN AUTO

HOLD

BP1

BP2

µ m

₂V A

2

AC

₁F

µ m

n

1

BP3

BP4

DC

M K Ω Hz

BATT

SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09

BP1 SCAN AUTO

A4 MANU A3

HOLD

B3

APO

A2

BP2

BP3

AC

DC

F4

E4

D4

B4

G4

C4

F3

E3

D3

F2

E2

B2

C2

-

G3

G2

BP4 BATT DP3

C3

DP2

D2

DP1

SEG10 SEG11 SEG12 SEG13 SEG14 SEG15

BP1

BP2

BP3

BP4

A1

F1

E1

D1

µ₂

m₂

V

M

K

Ω

n

µ₁

m₁

F

B1

G1

C1

A

Hz

Ver 2.9

17

10/06/25

ES51927

6000 Counts Smart DMM

LCD Backplane Waveform

V- +3.2

V-

V- +3.2

V-

V- +3.2

V-

V- +3.2

V-

V- +3.2

V-

4.2 LCD display on condition

LCD annunciates

Condition

V

A

Ω

F

In voltage measurement mode, and diode measurement mode.

In current measurement mode.

In resistance measurement mode, and continuity mode.

In capacitance measurement mode.

In continuity check mode.

In diode mode.

Hz

DC

In VAHZ frequency mode.

In DC voltage or DC current mode.

AC

In AC voltage or AC current mode.

SCAN

AUTO

MANU

When auto scan mode is selected

When automatic full scale range selection is enabled.

In manual mode.

When the reading is exceeding 30V in DCV or ACV, the DNAGER symbol will be

displayed on

When HOLD function is enabled. When delay-hold is selected, the HOLD symbol

will be blinking for 6 seconds.

In capacitor measurement mode and the full scale range is in the order of mF.

In capacitor measurement mode and the full scale range is in the order of uF.

HOLD

m₁

µ₁

n

m₂

In capacitor measurement mode and the full scale range is in the order of nF.

In voltage or current measurement mode and the full scale range is in the order of 10^-3.

In current measurement mode and the full scale range id in the order of uA.

µ₂

M

K

In resistance measurement mode and the full scale range is in the order of MΩ

In resistance measurement mode and the full scale range is in the order of KΩ

When auto power off function is enabled.

APO

Ver 2.9

18

10/06/25

ES51927

6000 Counts Smart DMM

Test Circuit

1. Voltage test

4. Current test

AGND

OVSG

AGND

100

1K

OR1

VR5

VR4

VR3

VR2

SGND

0.005

0.495

60A

10K

101K

1.111M

mA

ADO

4.5

D2

mA

uA

1.0u

D1

ADI

100K

50

A

15K

ACVL

ACVH

TEST5

mA

uA

IVSH

IVSL

15K

1.0u

450

10K

V

R

1

V

R

+4.7u

10K

5. Diode test

10M

-400mV

AGND

OVH

100

Voltage input

Z1

6V

Z2

PTC

1.5K

2. Resistance test

VR1

OVX

10M

22n

OHMC4

220n

VR2

OHMC3

OHMC2

OHMC1

1.111M

470n

47n

PTC

1.5K

OVSG

OVH

100

6. Low battery

Z1

6V

Z2

OVSG

100

OR1

VR5

VR4

VR3

VR2

1K

9V

10K

101K

1.111M

680K

BA

TT

LBAT9

SGND

AGND

0.1u

AGND

V-

270K

0V

3. Current test for clampmeter

7. EF test

100k

ADP

EFin+

EFin-

120M

VR

100K

SGND

AGND

ADP

R_L

R

SGND

AGND

VA+

VA-

400mV

Ver 2.9

19

10/06/25

ES51927

6000 Counts Smart DMM

Application Circuit

a.) AC average rectified circuit

1

2

3

4

5

6

V-

BT1

ZR3

3V

5.6V

uA

SW1

uA

SW2

D

C

B

A

D

C

B

A

SW SPDT

LCD Panel

C3

C4

10uF

ZR1

R1

ZR2

mA

0.1uF

450

J1

uA

SW3

ZR4

SEG01

SEG02

SEG03

SEG04

SEG05

SEG06

SEG07

SEG08

SEG09

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

BP1

C1

10uF

1

2

3

4

5

6

7

8

7.5V

C2

0.1uF

R2

45

mA

60A

SW4

9

U1

10

11

12

13

14

15

16

17

18

19

R3

ZR5

ZR6

4.5

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

75

74

73

72

71

70

69

68

67

66

65

64

63

62

61

60

59

58

57

56

55

54

53

52

51

SEG12

SEG13

SEG14

SEG15

CLAMP

VON

AON

FA

FUA

FC3

FC2

FC1

HOLD

SEL

VAHZ

RANGE

AGND

SEG12

SEG13

SEG14

SEG15

CLAMP

VON

AON

FA

FUA

FC3

FC2

FC1

HOLD

SEL

VAHz

RANGE

NC

BKLIT

EFEN

BP1

BP2

BP3

SW5

C9

LBAT

220nF

LBAT

CREF+

CREF-

CINT

CAZ

BUFF

RAZ

IVSH

IVSL

OVX

OVH

OVSG

OR1

VR5

VR4

VR3

VR2

TEST5

ACVL

ACVH

ADI

ADO

OHMC4

OHMC3

C7

C8

0.1uF

BP2

BP3

BP4

R4

0.495

R7

R8

R9

470K

60A

CON19

150K

100K

SW6

1

IVSH

IVSL

100K

R10

J2

J4

R6

R5

R11

100

ES51927

C6

VR1

20K

R12

R13

R14

R15

R18

100

1K

10K

101K

1.11M

TEST5

ACVL

ACVH

ADI

Function Switch

0.005

Gnd

220pF

R/C/D/Cont

V -

SW7

1.5K PTC

ZR8

R17

BKLIT

EFEN

BP1

BP2

BP3

SW SPST

SW13

BKLIT

RANGE

VAHZ

SEL

SW8

CLAMP

VON

AON

FA

ZR7

SW_non lock

SW_lock

SW14

1

ADO

BP4

ANNUNC

SW9

BP4

ANNUNC

BKOUT

IN

J3

SW_lock

SW15

VR1_10M

SW10

SW11

SW12

C11

22nF

C13

SW_lock

SW16

220nF

SW_lock

SW17

Average Circuit

C14

C15

470nF

47nF

HOLD

FUA

FC3

SW_lock

SW18

VR2

10K

R16

10K

TEST5

ADI

SW_lock

SW19

C10

4.7uF

APOSEL

BUZIN

SLEEP

FC2

C12

1uF

SW_lock

SW20

FC1

R21

15K

R22

15K

+ C17

1uF

R23

27K VR3

10K

1

C18

1uF

SW_lock

SW21

VR

+

R26

9K

EFEN

ADP

SW_lock

V -

D1

1N4148

D2

IN4148

ACVH

ADO

ZR9

5.6V

J5

R25

1K

BZ1

Buzzer

ACVL

Title

ES51927 6000 Counts Smart DMM

Size

B

Number

Revision

Application Circuit ( Average )

Date:

File:

30-Aug-2007

D:\Protel file\ES51928 Serial.ddb

Sheet of

Drawn By:

1

2

3

4

5

6

Notes:

1. The ESD protection circuits protect most of pins. However pins, V+, V-, AGND, DGND and VR1

are not protected enough because the parasitic effect must be decrease. Therefore enough external

protection is needed for assembling, carrying and keeping. In addition, components connecting to

these unprotected pins have to be soldered on board before the IC is soldered.

2. All the zener diodes above are used for IC protection. These protections are needed and these zener

diodes must be soldered on PCB first before soldering ES51927 on.

3. The OVX pin resistance have to be kept below 120kΩ for the capacitance mode accuracy (6/60nF

range). For higher voltage protection, additional configuration of PTC protection is necessary.

Ver 2.9

20

10/06/25

ES51927

6000 Counts Smart DMM

b.) AC RMS circuit

1

2

3

4

5

6

V-

BT1

ZR3

3V

5.6V

uA

SW1

uA

SW2

LCD Panel

SW SPDT

C3

C4

10uF

J1

ZR1

R1

ZR2

mA

SEG01

1

2

3

4

5

6

7

8

SEG02

SEG03

SEG04

SEG05

SEG06

SEG07

SEG08

SEG09

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

BP1

0.1uF

450

D

C

B

A

D

C

B

A

uA

SW3

ZR4

C1

10uF

7.5V

C2

0.1uF

R2

45

9

10

11

12

13

14

15

16

17

18

19

mA

60A

SW4

U1

R3

ZR5

ZR6

4.5

BP2

BP3

BP4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

75

74

73

72

71

70

69

68

67

66

65

64

63

62

61

60

59

58

57

56

55

54

53

52

51

SEG12

SEG13

SEG14

SEG15

CLAMP

VON

AON

FA

FUA

FC3

FC2

FC1

HOLD

SEL

VAHZ

RANGE

AGND

SEG12

SEG13

SEG14

SEG15

CLAMP

VON

AON

FA

FUA

FC3

SW8

C9

LBAT

220nF

LBAT

CREF+

CREF-

CINT

CAZ

BUFF

RAZ

IVSH

IVSL

OVX

OVH

OVSG

OR1

VR5

VR4

VR3

VR2

TEST5

ACVL

ACVH

ADI

ADO

OHMC4

OHMC3

C7

C8

0.1uF

CON19

R4

0.495

R8

R9

R10

R11

470K

60A

150K

100K

Function Switch

SW9

1

IVSH

IVSL

100K

J2

J3

R6

FC2

FC1

R5

R12

100

V -

ES51927

C6

HOLD

SEL

VAHz

RANGE

NC

BKLIT

EFEN

BP1

BP2

BP3

BP4

ANNUNC

BKOUT

VR1

20K

R13

R14

R15

R16

R17

100

1K

10K

101K

1.11M

0.005

Gnd

220pF

BKLIT

RANGE

VAHZ

SEL

SW5

SW6

SW7

SW11

SW12

R/C/D/Cont

SW_non lock

SW10

1.5K PTC

ZR8

R7

BKLIT

EFEN

BP1

BP2

BP3

BP4

ANNUNC

SW SPST

SW_non lock

ACVL

ACVH

ZR7

ADO

1

IN

SW16

ACV / RMS

J4

HOLD

C10

22nF

C12

SW_lock

220nF

C13

C14

470nF

47nF

VR1_10M

V -

ES7PWR

APOSEL

BUZIN

SLEEP

SW13

CLAMP

C11

1uF

TRMS Circuit

SW_lock

SW14

VON

AON

FA

R19

27K VR2

10K

1

R18

5K

VR

R22

9K

SW_lock

SW15

-VS_ES7 +VS_ES7

-VS_ES7

+VS_ES7

ADP

V -

SW_lock

SW17

1

2

3

4

8

7

6

5

2

ZR9

5.6V

RL

Vin

COM

+ VS

PwrDown Vout

-

6

ACVH

J5

SW_lock

SW18

ES7PWR

3

R27

1K

U3

TL061

+

FUA

FC3

BZ1

Buzzer

- VS Cav

SW_lock

SW19

U2 ES7

C18 2.2uF

-VS_ES7

-VS_ES7 +VS_ES7

R23

47K

+ C20

2.2uF

R24

10K

R25 1.5K

SW_lock

SW20

C16

C17

+

FC2

VR4

100K

+

SW_lock

SW21

C19

1uF ADO

10uF

Title

FC1

VR3

50K

ES51927 6000 Counts Smart DMM

SW_lock

SW22

Size

B

Number

Revision

EFEN

Application Circuit ( TRMS )