ES51926 - CyrusTek

ES51926
3000 Counts Smart DMM
Features
General description

3000 counts LCD display

3V DC power supply
ES51926 is an integrated ADC with 3000 counts

Conversion rate: 4 times/s (voltage mode)
LCD display driver. It could support fully

Full automatic measurement:
automatic DMM function measurement. In
*Voltage/Current: AC/DC auto scanning
voltage or current mode, the AC or DC signals
& auto range: 3.000V~1000V

auto scanning. In R/D/C (passive component)
*Resistance/Diode/Capacitance(RDC scan)
mode,
(Taiwan patent no.: 326361)
capacitance or diode measurements are allowed
Auto scanning & auto range:
by fully automatic detection. A single key and
Resistance: 300.0Ω~3.000MΩ
simple switch could select all measurements.
Capacitance: 3.000nF~300.0uF
Expensive and bulky mechanical range switches
resistance
(including
continuity),
(Taiwan patent no.: 323347,453443)
are not required. A non-contact electric field
Push functions
detector (EF mode) is built-in for ac voltage
Function selection by single key
measurement also. Other features including
Range change function
range control, data hold, max/min hold, VAHz
Hold function
and back light function are available. For power
MAX/MIN function
saving, an auto power off & re-power on scheme
VAHZ function
are built-in. A sleep output is the indication of
Back light function
entering auto power off mode.

Support non-contact voltage detection

High voltage (> 30V) indication of LCD
display for voltage measurement
(Taiwan patent no.: 234661)

Built-in HCF(high crest factor detection)
function in AC mode

OL level selection (600V/1000V/1500V)

Band-gap reference voltage output

Auto power off (3min. or 10min.) &
re-power on

Sleep output indication

On-chip buzzer driver

Low battery detection
Application

Smart digital multi-meter

Smart clamp meter
Ver 3.7
1
13/03/11
ES51926
3000 Counts Smart DMM
SEG11
SEG10
NC
NCV_EN
SEG09
SEG08
SEG07
SEG06
SEG05
SEG04
SEG03
SEG02
SEG01
OSC2
OSC1
BKSEL
CESEL
C+
CVVV+
V+
DGND
AGND
ES51926
NC
nF_OPT
NC
NC
NC
ACEN
BUZOUT
APOSEL
BUZIN
SLEEP
R1K
R9K
CA+
CANC
VR1
VAVA+
ADP
SGND
VR
VRH
PWRSEL
OHMC1
OHMC2
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
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
AGND
LBAT
CREF+
CREFCINT
CAZ
BUFF
RAZ
IVSH
IVSL
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ACVH
ADI
ADO
OHMC4
OHMC3
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
SEG12
SEG13
SEG14
SEG15
CLAMP
VON
AON
FA
FUA
FC3
FC2
FC1
HOLD
SEL
VAHz
RANGE
MAX/MIN
BKLIT
EFEN
BP1
BP2
BP3
BP4
ANNUNC
BKOUT
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
Pin Assignment
Pin Description
Pin No
Symbol
Type
3
4
5
6
7
8
CREF+
CREFCINT
CAZ
BUFF
RAZ
I/O
I/O
O
I
O
O
9
10
11
IVSH
IVSL
OVX
I
I
I
1
2
Ver 3.7
AGND
LBAT
P
I
Description
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)
Positive connection for reference capacitor.
Negative connection for reference capacitor.
Integrator output. Connect to integral capacitor
Auto-zero capacitor connection.
Buffer output pin. Connect to integral resistor
Buffer output pin in high-speed mode. Connect to high-speed integral
resistor.
High current measurement input.
Low current measurement input
Input high voltage for resistance/capacitor measurement
2
13/03/11
ES51926
3000 Counts Smart DMM
12
13
14
15
16
17
18
19
20
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
I
I
O
O
O
O
O
I/O
I
21
ACVH
I
22
23
24
25
26
27
28
29
30
31
32
33
ADI
ADO
OHMC4
OHMC3
OHMC2
OHMC1
PWRSEL
VRH
VR
SGND
ADP
VA+
I
O
O
O
O
O
I
O
I
I
I
I
34
VA-
I
35
36
37
38
39
40
41
42
43
44
45
46 – 48
49
50
51
VR1
NC
CACA+
R9K
R1K
SLEEP
BUZIN
APOSEL
BUZOUT
ACEN
NC
nF_OPT
NC
BKOUT
I
I/O
I/O
O
O
O
I
I
O
O
I
O
52
ANNUNC
O
53
54
55
56
57
58
59
60
BP4
BP3
BP2
BP1
EFEN
BKLIT
MAX/MIN
RANGE
O
O
O
O
I
I
I
I
Ver 3.7
Output connection for resistance/capacitor measurement
Sense low voltage for resistance measurement
Reference resistor connection for 300.0Ω range
Voltage measurement ÷10000 attenuated (1000V)
Voltage measurement ÷1000 attenuated (300.0V)
Voltage measurement ÷100 attenuated (30.00V)
Voltage measurement ÷10 attenuated (3.000V)
Test pin
DC signal low input in ACV/ACA mode. Connect to negative output of
external AC to DC converter.
DC signal high input in ACV/ACA mode. Connect to positive output of
external AC to DC converter.
Negative input of internal AC to DC OP Amp.
Output of internal AC to DC OP Amp.
Filter capacitor connection for resistance mode
Filter capacitor connection for resistance mode
Filter capacitor connection for resistance mode
Filter capacitor connection for resistance mode
Pulled to V- to disable the power function of SEL key
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-.
For ADP mode. De-integrating voltage negative input. The input should b
lower than VA+.
Measurement input.
Not connected
Negative auto-zero capacitor connection for capacitor measurement
Positive auto-zero capacitor connection for capacitor measurement
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.
Not connected
Pulled to V- to enable the residual capacitance reduction mode.
Not connected
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.
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.
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.
Pulse to V- to enable MAX/MIN function.
Pulse to V- to enable manual mode and manual range selection.
3
13/03/11
ES51926
3000 Counts Smart DMM
61
62
63
64
65
66
67
68
69
70
71
72 – 77
78
79
80 – 88
89
90
VAHz
SEL
HOLD
FC1
FC2
FC3
FUA
FA
AON
VON
CLAMP
SEG15 – 10
NC
NCV_EN
SEG09 - 01
OSC2
OSC1
I
I
I
I
I
I
I
I
I
I
I
O
I
O
I
O
91
BKSEL
I
92
93
94
95
96
97
98
99
100
CESEL
C+
CVVV+
V+
DGND
AGND
I
O
O
P
P
P/O
P/O
G
G
Pulse to V- to enable VAHz mode.
Pulse to V- to select target measurement
Pulse to V- to enable HOLD function.
Switch 1 for function selection.
Switch 2 for function selection.
Switch 3 for function selection.
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
Not connected
Individual EF function selection
LCD segment line 01 – 09
Crystal oscillator input connection
Crystal oscillator output connection
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.
If BKLIT is back to high level, the BKOUT would be inactive.
OL selection feature control pin.
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.
Negative supply voltage. Connecting to battery negative terminal.
Output of on-chip DC-DC converter.
Output of on-chip DC-DC converter.
Digital ground.
Analog ground.
Absolute Maximum Ratings
Characteristic
Supply Voltage (V- to AGND)
Analog Input Voltage
V+
AGND/DGND
Digital Input
Power Dissipation. Flat Package
Operating Temperature
Storage Temperature
Ver 3.7
Rating
-4V
V- -0.6 to V+ +0.6
V+ ≥ (AGND/DGND+0.5V)
AGND/DGND ≥ (V- -0.5V)
V- -0.6 to DGND +0.6
500mW
0℃ to 70℃
-25℃ to 125℃
4
13/03/11
ES51926
3000 Counts Smart DMM
Electrical Characteristics
TA=25℃, V- = -3V
Parameter
Power supply
Operating supply current
In Scan AC/DC mode
Voltage roll-over error
Voltage nonlinearity
Input Leakage
Low battery flag voltage
Zero input reading
Peak to peak backplane
drive voltage
Counter time base period
Reference voltage and open circuit
voltage for 300Ω measurement
Open circuit voltage for Ω
measurement (except 300Ω)
Internal pull-high to 0V
current
AC frequency response at 6.000V
Range
AC input response for scan mode
AC/DC voltage scan mode
sensitivity@1kHz
AC/DC current scan mode
sensitivity@1kHz
RDC scan mode RES sensitivity
Symbol
Test Condition
VIDD Normal operation
ISS In sleep mode
REV 10MΩ input resistor
Min.
-3.5
—
—
—
Typ.
-3.0
2.5
0.6
—
Max
-2.5
—
2.5
±0.1
Units
V
mA
µA
%F.S1
Best case straight
NLV line
—
—
±0.1
%F.S
-10
-2.4
-000
1
-2.3
000
10
-2.2
+000
PA
V
counts
3.0
3.15
3.3
V
—
1
—
sec
-1.33
-1.23
-1.13
V
-0.86
-0.78
-0.70
V
—
1.2
—
µA
V- to AGND
10MΩ input resistor
-3.5V≤ V ≤-2.2V
VREF
fOSC = 4MHZ
100KΩ resistor
between VRH and
AGND
Ω and Continuity
Mode
Between V- pin and
HOLD, RANGE,
SEL,FC1-3,FUA,
FA, VON, AON,
CLAMP, BKLIT,
MAXMIN
±1%
±5%
VR1(10MΩ input
impedance)
ADP, IVSL and IVSH
Parasitic capacitance
allowed in 3.000MΩ
range
Forward voltage
RDC scan mode DIODE sensitivity
RDC scan mode CAP sensitivity
Reference voltage temperature
100KΩ
resister
coefficient
VRH
TCRF Between
0℃<TA<70℃
Capacitance measurement
accuracy
3nF – 3.0µF
30µF ~ 30mF
—
—
10
40-400
—
400-2000 —
—
50000
HZ
Hz
300
450
600
mV
8
10
12
mV
—
—
200
pF
—
400
0.8
—
—
—
V
pF
—
50
—
ppm/℃
-1.5
-5
-2.0
—
—
—
1.5
5
2.0
%F.S
counts
%F.S
-5
—
5
counts
Note:
1.Full Scale
Ver 3.7
5
13/03/11
ES51926
3000 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
VR2
VR3
VR4
VR5
Full Scale Range
300.0mV*
3.000V**
30.00V
300.0V
1000V***
Divider Ratio
1
1/10
1/100
1/1000
1/10000
Resister Connection
VR1 (10MΩ)
VR2 (1.111MΩ)
VR3 (101KΩ)
VR4 (10KΩ)
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
ES51926 has a OL display selection feature archived by configuring a CESEL
pin. If pin CESEL is connected to V-, ES51926 will have a 600.0V overflow
level in DCV and ACV mode. If pin CESEL is connected to DGND, the
ES51926 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
VDGND
Floating
Ver 3.7
DCV
600.0V
1010V
1500V
6
ACV
600.0V
1010V
1010V
13/03/11
ES51926
3000 Counts Smart DMM
1.1.2 HCF detection
ES51926 provides detection of high-crest-factor (HCF) signal in ACV auto range
mode. ES51926 senses the signal and determines it as HCF if the Vpp is large
enough. Once the signal is determined as HCF, ES51926 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=200V, Vrms=40V(CF=5) was applied,
traditional DMM might stay at 30V 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 300V range and exhibits
more accurate results.
1.1.3 EF mode
ES51926 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 or set control mode individually. 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 3.7
7
13/03/11
ES51926
3000 Counts Smart DMM
1.2 Current Measurement
1.2.1 For multi-meter application
ES51926 has 2 automatic and 1 manual current measurement modes for
multi-meter. The following table summarizes the full-scale range of each mode.
When ES51926 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
Automatic2
Manual
Full Scale
300.0µA / 3000µA
30.00mA / 300.0mA
30.00A
Input Terminal
IVSL/IVSH V.S. SGND
IVSL/IVSH V.S. SGND
IVSH V.S. SGND
Full scale
150.0mV
150.0mV
150.0mV
1.2.2 For clamp meter application
ES51926 has 2 automatic and 4 manual current measurement modes for Clamp
meter. The following table summarizes the full-scale range of each mode. When
ES51926 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 ES51926 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
Ver 3.7
Full Scale
300.0A / 3000A
30.00A / 300.0A
3.000A
30.00A
300.0A
3000A
Input Terminal
IVSL/IVSH V.S. SGND
IVSL/IVSH V.S. SGND
ADP V.S. SGND
ADP V.S. SGND
ADP V.S. SGND
ADP V.S. SGND
8
Full scale
300.0mV
300.0mV
300.0mV
300.0mV
300.0mV
300.0mV
13/03/11
ES51926
3000 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
OR2
OR3
OR4
OR5
OR6
Full Scale Range
300.0Ω*
3.000KΩ
30.00KΩ
300.0KΩ
3.000MΩ
30.00MΩ**
Relative Resistor
OR1
VR5
VR4
VR3‖VR1
VR2‖VR1
VR1
Equivalent value
100Ω
1KΩ
10KΩ
100KΩ
1MΩ
10MΩ
Note: * When auto scan mode is set, continuity check is implemented in this range
** When auto scan mode is set, the 30.00MΩ range is omitted
1.3.1 Continuity check
Continuity check shares the same configuration with 300.0Ω 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 3.000V 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 3.7
9
13/03/11
ES51926
3000 Counts Smart DMM
1.5 Capacitance Measurement
The following table summarizes the eight ranges of capacitance measurement
mode:
Configuration
C1
C2
C3
C4
C5
C6
C7
C8
Full Scale Range
3.000nF***
30.00nF
300.0nF
3.000uF
30.00uF
300.0uF
3.000mF*
30.00mF**
Relative Resistor
20kΩVR+100kΩ
20kΩVR+100kΩ
101kΩ
10kΩ
R9K / R1K
R9K / R1K
R9K / R1K
R9K / R1K
Note:
* & **
***
The C7-C8 both range is not available for auto scan mode
When the nF_OPT pin is pulled to V- level, the residual capacitance mode is enabled. Connect
a compensation capacitance to OVH terminal for lower capacitance measurement accuracy if
necessary.
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
ES51926 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 ES51926 when any of the push key,
except for HOLD, is pressed down simultaneously.
Ver 3.7
10
13/03/11
ES51926
3000 Counts Smart DMM
1.6.2 Sleep output
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. 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 3.7
11
13/03/11
ES51926
3000 Counts Smart DMM
2.
Functional Modes Table
Measurement mode depends on the logic level of FC1, FC2, FC3, FUA, FA,
VON, AON, NCV_EN and CLAMP.
FC1 FC2 FC3 FUA
1
1
1
1
1
1
1
1
1
0
0
0
1
1
X
X
X
X
X
X
X
X
X
1
0
1
0
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
X
X
1
0
0
X
X
1
0
X
X
X
X
X
FA
X
X
0
0
1
X
X
0
0
X
X
X
X
X
VON
X
X
X
X
X
1
1
0
0
X
0
0
0
0
AON
0
0
1
1
1
X
X
X
X
X
X
X
X
X
NCV_EN CLAMP
1
0
1
1
1
1
0
1
1
1
1
1
1
1
0
0
0
0
0
1
1
1
1
X
1
1
1
1
Functional Mode(pushing SEL key)
VAUTOVACVDCEF*VAUTO…
EF
IAUTOIACIDCIAUTO…(uA)
IAUTOIACIDCIAUTO…(mA)
IAUTOIACIDCIAUTO…(A)
VAUTOVACVDCVAUTO…
EF
IAC(300.0A/3000A)
IAC(30.00A/300.0A)
RDCAUTORDCRDCAUTO…
IAUTOIACIDCIAUTO…(3.000A)
IAUTOIACIDCIAUTO…(30.00A)
IAUTOIACIDCIAUTO…(300.0A)
IAUTOIACIDCIAUTO…(3000A)
Input
VR1,ADP
ADP
IVSH/IVSL
IVSH/IVSL
IVSH
VR1
ADP
IVSH/IVSL
IVSH/IVSL
VR1
ADP
ADP
ADP
ADP
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, MAX/MIN, and VAHz functions. The following
table lists the available function versus every measurement mode.
SEL
RANGE
HOLD MAX/MIN
VSCAN
O
X
O
X
VAC
O
O
O
O
VDC
O
O
O
O
EF
O
X
X
X
ISCAN
O
X
O
X
IAC
O
O*
O
O
IDC
O
O*
O
O
RDCSCAN
O
X
O
X
Resistance
O
O
O
O
Continuity
O
X
O
O
Diode
O
X
O
O
Capacitance
O
O
O
O
Note: For ADP input, RANGE is not available
Ver 3.7
12
VAHz
O
O
O
X
O
O
O
X
X
X
X
X
BKLIT
O
O
O
O
O
O
O
O
O
O
O
O
13/03/11
ES51926
3000 Counts Smart DMM
3.1 Select function
When power on or SEL key is pressed longer than one second, ES51926 will be
power-on reset to auto scan mode, which scanning mode is determined by
[FC1-FC3] function set. In auto scan mode, the ES51926 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 ES51926 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 Vterminal could re-power on the ES51926. The following figure shows the state
transition.
Note: If PWRSEL (pin28) is pulled to V-, the power control feature for SEL key
will be disabled.
Push SEL key < 1s
V/A
ac/dc auto scan
Push SEL key > 1s
Power on reset
AC mode
measurement
DC mode
measurement
EF* mode
measurement
Push SEL key > 2s  enter power down mode
R/D/C
auto scan
Continuity
measurement
Resistance
measurement
Diode
measurement
Capacitance
measurement
Push SEL key < 1s
Note: * Available when EF_EN is active only
Ver 3.7
13
13/03/11
ES51926
3000 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.
Automatic
Mode
1 push < 1 sec
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 will be 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.
Ver 3.7
14
13/03/11
ES51926
3000 Counts Smart DMM
3.4 Max/Min + Hold function
The meter displays the maximum or minimum value of the input in Max/Min
mode. When MAX/MIN is pressed for the first time, the meter displays the
maximum value. The meter displays the minimum value, when it is pressed again.
When MAX/MIN is pressed for the third time, the meter displays current value.
The meter returns to normal operation if MAX/MIN is pressed and held for longer
than one second. Pressing HOLD key in Max/Min mode makes the meter stop
updating the maximum or the minimum value.
1 push<1s
Original state
(Automatic/manual)
1 push>1s
1 push>1 sec
1 push>1 sec
“MAX” active 1push<1s “MIN” active 1push<1s “Max” “MIN” blink
current value
min value
max value
Push HOLD
1push<1s
Push HOLD
Push HOLD
“MAX”“MIN” “H” blink
“MIN” “H” active
“MAX” “H” active
hold max value. 1push<1s hold min value. 1push<1s hold current value.
1push<1s
3.5 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
FR1
FR2
FR3
Ver 3.7
Range
3.000KHz
30.00KHz
100.0KHz
15
13/03/11
ES51926
3000 Counts Smart DMM
3.6 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-
4.
Configuration
Normal back light function
Auto back light function
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 3.7
16
13/03/11
ES51926
3000 Counts Smart DMM
4.1 LCD configuration
S1
BP1
S2
S3
S4
S5 S6
SCAN AUTO MANU
S14 S12
S9 S10 S11
S15
S7 S8
HOLD
MAX MIN
APO
BP2
BP3
S13
µ2 m2 V A
AC
n µ1 m1 F
DC
M K Ω Hz
BP4 BATT
SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09
BP1 SCAN AUTO
BP2
AC
BP3
DC
BP4 BATT DP3
A4
F4
E4
D4
MANU
B4
G4
C4
A3
F3
E3
D3
HOLD
B3
G3
C3
F2
E2
DP2
APO
A2
G2
D2
B2
C2
DP1
SEG10 SEG11 SEG12 SEG13 SEG14 SEG15
BP1
A1
BP2
F1
BP3
BP4
Ver 3.7
µ2
M
n
MAX
B1
m2
K
µ1
MIN
E1
G1
V
Ω
m1
D1
C1
A
F
17
Hz
13/03/11
ES51926
3000 Counts Smart DMM
LCD Backplane Waveform
V- +3.2
VV- +3.2
VV- +3.2
VV- +3.2
VV- +3.2
V-
4.2 LCD display on condition
LCD annunciates
V
A
Ω
F
Hz
DC
AC
SCAN
AUTO
MANU
HOLD
Max / Min
m1
µ1
n
m2
µ2
M
K
APO
Ver 3.7
Condition
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.
In VAHZ frequency mode.
In DC voltage or DC current mode.
In AC voltage or AC current mode.
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.
When Max or Min function is enabled.
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.
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.
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.
18
13/03/11
ES51926
3000 Counts Smart DMM
Test Circuit
1. Voltage test
4. Current test
AGND
OVSG
100
1K
10K
101K
1.111M
D1
OR1
VR5
VR4
VR3
VR2
ADO
D2
+1.0u
ADI
ACVL
ACVH
TEST5
15K
15K
10K
+4.7u
10K
0.005
AGND
SGND
30A
0.495
mA
4.5
A
mA
uA
V
R
1
V
R
mA
50
100K
uA
uA
100K
5. Diode test
10M
AGND
-400mV
Voltage input
22n
470n
PTC
1.5K
47n
100
Z1
6V
Z2
100
1K
10K
101K
1.111M
OVH
100
Z1
6V
Z2
2. Resistance test
220n
IVSH
IVSL
450
PTC
1.5K
10M
OVX
OHMC4
OHMC3
1.111M
OHMC2
VR1
VR2
OVSG
OHMC1
OVH
OVSG
6. Low battery
OR1
VR5
VR4
VR3
VR2
9V
680K
BA
SGND
AGND
TT
270K
LBAT9
0.1u AGND
V-
0V
3. Current test for clampmeter
7. EF test
RL
Ver 3.7
VR
R
EFin+
100K
ADP
EFin-
SGND
AGND
100k
60M
ADP
SGND
AGND
VA+
400mV
19
VA-
13/03/11
D
1
1
ZR1
ZR5
R1
450
R2
SW2
ZR2
SW3
uA
uA
mA
mA
60A
2
R6 100K
C24
R11
20K
IVSH
IVSL
SW23
Power Switch
5.6V
10uF
V-
470K
150K
100K
100K
220nF
220nF
7.5V
0.1uF
V + ZR11
C7
C8
C26
(Optional)
100
C6
220pF
R7
R8
R9
R10
C22
10uF
C23 0.1uF
C21
ZR10
Regulator DC3.0V
VR1
TEST5
ADI
R12
R13
R14
R15
R18
C9
0.1uF
3
BT1
3V
5.6V
0.1uF
10uF
ZR3
C3
7.5V
ZR4
C4
C2
0.1uF
C1
10uF
U1
AGND
LBAT
CREF+
CREFCINT
CAZ
BUFF
RAZ
IVSH
IVSL
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ACVH
ADI
ADO
OHMC4
OHMC3
470nF
C13
220nF
1
LBAT 2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
100
1K
10K
101K
1.11M
TEST5
ACVL
ACVH
ADI
ADO
C11
22nF
C14
47nF
ADP
27K VR3
VR
1uF
C15
C12
+
ZR6
SW4
SW5
SW6
SW24
SWSPST
R/C/D/Cont
4.7uF
R17 1.5K PTC
ZR7
ZR8
C10
R23
+
45
R3
4.5
R4
0.495
R5
0.005
SWSPST
SW7
R22
15K
10K
R/C/D/Cont
VR1_10M
R16
C18
1uF
ACVH
+
1
IN
10K
IN4148
D2
ADO
ACVL
3
+
uA
SW1
J4
J2
SWSPDT
mA
Gnd
60A
1
J3
VR2
Average Circuit
R21
15K
+ C17
1uF
1N4148
D1
2
V-
4
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
NCV_EN
10K
1
J5
ES51926
C16
C19
220nF
100K
C
B
A
1
C5 0.47uF
VR1_10M R20
+
4MHz
Y1
CESEL
BKSEL
+
SEG10
SEG11
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
R26
9K
R25
1K
4
ZR9
5.6V
BZ1
Buzzer
V-
nF_en
ES7PWR
APOSEL
BUZIN
SLEEP
SEG12
SEG13
SEG14
SEG15
CLAMP
VON
AON
FA
FUA
FC3
FC2
FC1
HOLD
SEL
VAHz
RANGE
MAX/MIN
BKLIT
EFEN
BP1
BP2
BP3
BP4
ANNUNC
BKOUT
AGND
DGND
V+
V+
VVCC+
CESEL
BKSEL
OSC1
OSC2
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
NCV_EN
NC
SEG10
SEG11
R24
+
OHMC2
OHMC1
PWRSEL
VRH
VR
SGND
ADP
VA+
VAVR1
NC
CACA+
R9K
R1K
SLEEP
BUZIN
APOSEL
BUZOUT
ACEN
NC
NC
NC
nF_OPT
NC
26
27
PWRSEL 28
56K 29
30
31
32
33
VA+
34
VA10M 35
36
37
470nF
38
39
40
41
42
43
44
45
46
47
48
49
50
R19
+
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
MAX/MIN
BKLIT
EFEN
BP1
BP2
BP3
BP4
ANNUNC
5
5
LCD Panel
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
BP1
BP2
BP3
BP4
BKLIT
J1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
CON19
SW8
SW11
SW10
MAX/MIN SW9
VAHZ
SW12
RANGE
SEL
SW13
Number
SW_nonlock
SW_nonlock
SW_nonlock
SW_nonlock
SW_nonlock
17-May-2012
F:\Protelfile\KA025\KA025.ddb
V-
CLAMP
VON
AON
FA
FUA
FC3
FC2
FC1
EFEN
nF_en
6
SW14
SW_lock
SW16
SW_lock
SW15
SW_lock
SW18
SW_lock
SW17
SW_lock
SW19
SW_lock
SW20
SW_lock
SW21
SW_lock
SW22
SW_lock
SW25
6
Revision
SW_lock
NCV_EN SW26
NCV_EN
Sheet of
Drawn By:
Application Circuit ( Average )
ES51926 3000 Counts Smart DMM
HOLD
SW_nonlock
Function Switch
Title
Size
B
Date:
File:
V-
D
C
B
A
13/03/11
20
Ver 3.7
+
3000 Counts Smart DMM
ES51926
Application Circuit
a.) AC average rectified circuit
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 ES51926 on.
3. The OVX pin resistance have to be kept below 120kΩ for the capacitance mode accuracy (3/30nF
range). For higher voltage protection, additional configuration of PTC protection is necessary.
D
C
1
J1
uA
2
1
ZR1
ZR5
R1
450
R2
45
R3
4.5
R4
0.495
R5
0.005
SW2
ZR2
SW3
SW4
ZR6
SW8
SW9
uA
uA
mA
mA
60A
R/C/D/Cont
SWSPST
SW25
SWSPST
SW10
+VS_ES7
R/C/D/Cont
VR1_10M
500K
R6
ZR8
1.5K PTC
100K
3
ZR7
R7
ACVH
2.2uF
+ C20
VR1
Regulator DC3.0V
SW24
Power Switch
5.6V
V-
4
0.1uF
BT1
3V
10uF
5.6V
0.1uF
ZR3
C3
7.5V
ZR4
C4
C1
10uF
V + ZR11
7.5V
220nF
220nF
470K
150K
100K
100K
470nF
AGND
LBAT
CREF+
CREFCINT
CAZ
BUFF
RAZ
IVSH
IVSL
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ACVH
ADI
ADO
OHMC4
OHMC3
C2
0.1uF
C9
1
LBAT 2
3
4
5
6
7
8
9
10
11
12
13
14
100
15
1K
16
10K
17
101K
18
1.11M
19
20
ACVL
21
ACVH
22
23
24
25
ADO
C13
ADP
27K VR2
VR
1uF
47nF
C11
C14
C12
220nF
10uF
R13
R14
R15
R16
R17
SW_lock
R20
C10
22nF
0.1uF
C7
C8
C6
220pF
R8
R9
R10
R11
ACV / RMS
SW17
C26
ZR10
C23
IVSH
IVSL
C28
(Optional)
100
C24
10uF
C25 0.1uF
20K
R12
+
VR4
8
7
6
5
ADO
+
1
IN
J3
J2
SWSPDT
Gnd
60A
mA
SW1
1
J4
-VS_ES7
10K
1uF
1
COM
RL
2
+
V
S
Vin
3
Vout
Pw
rDow
n
4
Cav
- VS
U2
ES7
+VS_ES7
C19
2.2uF
C18
+
V-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
CON19
SW_nonlock
SW_nonlock
SW_nonlock
SW_nonlock
SW_nonlock
SW_nonlock
V-
R18
47K
+
LCD Panel
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
BP1
BP2
BP3
BP4
SW5
Function Switch
BKLIT
SW7
MAX/MIN SW6
RANGE
SW12
SW11
SEL
SW13
VAHZ
HOLD
SW14
SW_lock
SW15
R19
R24
150
V-
C5 0.47uF
10K
1
J5
VR1_10M R22
CLAMP
TRMS Circuit
10uF
C17
+
C15
C21
SW_lock
SW16
SW_lock
SW18
SW_lock
SW19
ES7PWR
C16
-VS_ES7 +VS_ES7
10uF
50K
4
100K
R26
VON
AON
FA
SW_lock
SW20
SW_lock
SW21
SW_lock
SW22
SW_lock
SW23
VR3
3
5
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
NCV_EN
4MHz
Y1
CESEL
BKSEL
+
SEG10
SEG11
5
ZR9
Number
BZ1
Buzzer
5.6V
V-
17-May-2012
F:\Protelfile\KA025\KA025.ddb
U1
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
MAX/MIN
BKLIT
EFEN
BP1
BP2
BP3
BP4
ANNUNC
ES51926
Sheet of
Drawn By:
Application Circuit ( TRMS )
ES51926 3000 Counts Smart DMM
R23
9K
R27
1K
Title
Size
B
Date:
File:
nF_en
ES7PWR
APOSEL
BUZIN
SLEEP
SEG12
SEG13
SEG14
SEG15
CLAMP
VON
AON
FA
FUA
FC3
FC2
FC1
HOLD
SEL
VAHz
RANGE
MAX/MIN
BKLIT
EFEN
BP1
BP2
BP3
BP4
ANNUNC
BKOUT
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
AGND
DGND
V+
V+
VVCC+
CESEL
BKSEL
OSC1
OSC2
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
NCV_EN
NC
SEG10
SEG11
OHMC2
OHMC1
PWRSEL
VRH
VR
SGND
ADP
VA+
VAVR1
NC
CACA+
R9K
R1K
SLEEP
BUZIN
APOSEL
BUZOUT
ACEN
NC
NC
NC
nF_OPT
NC
R21
+
+
26
27
PWRSEL 28
56K 29
30
31
32
33
VA+
34
VA10M 35
36
470nF
37
38
39
40
41
42
43
44
45
46
47
48
49
50
220nF
FUA
FC3
FC2
FC1
nF_en
NCV_EN
SW_lock
SW26
2
+
6
6
Revision
D
C
B
A
13/03/11
21
Ver 3.7
B
A
NCV_EN
1
+
3000 Counts Smart DMM
ES51926
b.) AC RMS circuit
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 ES51926 on.
3. The OVX pin resistance have to be kept below 120kΩ for the capacitance mode accuracy (3/30nF
range). For higher voltage protection, additional configuration of PTC protection is necessary.
ES51926
3000 Counts Smart DMM
Package Information
7.1
100 Pin LQFP Package
7.2
Dimension Parameters
Ver 3.7
22
13/03/11