ES237 6000 Counts DMM Features ＊ Back Light function 6,000 counts LCD display with 31 analog bar-graph ＊ KEY function LQFP 128L package ＊ Data Hold and delayed-hold function 3V DC power supply ＊ Range change function Slow ADC Conversion rate : 3 times/s ＊ Semi-auto calibration operation Bar-graph ADC conversion rate : 30 times/s Full automatic measurement (Taiwan patent no.: 367334) ＊ Voltage measurement : 600.0mV, 6.000V – 1000V (Taiwan patent no.: 362409) ＊ Current measurement : μA/mA/A Band-gap reference voltage output ＊ Frequency with Voltage or Current : Voltage overflow selection ( DC / AC : 1010V, DC / ＊ Resistance measurement : AC : 610V) Serial data output ( RS232 format ) LCD segment check when power on 6.000nF – 60.00mF Auto power off ( 30min / 15min ) ( Taiwan patent no.: 323347, 453443 ) Sleep state indicative signal output Re-power on On-chip buzzer driver Low battery detection 60.00Ω – 60.00MΩ ＊ Capacitance measurement : ＊ Capacitance measurement for Clampmeter mode : 6.000nF – 60.00mF ＊ Smart auto check for R / S / D / C mode (Buz. On when R < 30Ω) ES237 is an integrated analog-to-digital converter with 6,000-count LCD with bar-graph display, automatic range selection, and 3V DC power supply. Automatic range selection is provided for ACV/DCV measurement, resistance measurement, current measurement, capacitance measurement, and frequency counter. Expensive and bulky mechanical range switches are not required. Other features include relative value display, offset removing feature for DCA clamp mode, data holding, maximum and minimum value holding, duty cycle measurement, diode measurement, temperature measurement, continuity checking, low battery detection, auto power off, re-power on, backlight driver, buzzer driver and RS232 data output. (Taiwan patent no.: 326361) ＊ Not contact AC electric field detection ＊ Frequency counter : 600.0Hz – 60.00MHz ＊ Duty cycle measurement : 5% – 95% (< 10kHz) Diode measurement & continuity check Hazardous AC/DC voltage (HV) indication 4 ADP modes with external reference voltage and independent “ADP” user-defined segment on LCD Temperature mode with internal scale translation circuit from 0C to 0F K-type thermocouple reference table compensation (-200 ~ 1350oC range) Description Resistance : 0.0Ω – 6.000MΩ Capacitance : 0.500nF – 600.0uF Low pass filter mode for ACA/ACV measurement Push functions : ＊ VAHz function ＊ MAX/MIN function ＊ Relative function ＊ Zero function: DCA clampmeter only V 2.2 1 2015/12/15 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 26 27 28 29 30 31 32 33 34 35 36 37 38 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 V 2.2 RSOUT OSC1 OSC2 RS232 VBAR APOSEL VST TSEL DIS SEL1 SEL2 CESEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 Digital multimeter Clamp meter NC HZ MMX REL BKLIT KEY HOLD RANGE FC5 FC4 FC3 FC2 FC1 SLACDC CN CP LBAT9 VVV+ V+ DGND AGND AGND NC NC IVS ADP TEMPin CLAMPin CHP CHN CIH BUFH CAZH CLN CLP CIL CAZL BUFL RAZ VRH DACO VR_CLAMP VR_ADP OHMC4 OHMC3 OHMC2 OHMC1 OVSG OR1 VR5 VR4 VR3 VR2 ACVL ACVH ADI ADO TEST5 SGND VR1 mVin LPFout ES237 6000 Counts DMM Application Pin Assignment 128L LQFP package Cyrustek. com.tw ES237 2 SEG27 SEG28 SEG29 BP1 BP2 BP3 BP4 ALARM ALARM1 BKOUT BZOUT SCLP SDAP CALENP FREQ SLEEP OVH1 OVH OVX R1K R10K CAP CAN LPC3 LPC2 LPC1 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 2015/12/15 ES237 6000 Counts DMM Pin Description Pin No Symbol Type Description 1 IVS I Measurement input in uA/mA current mode. 2 ADP I Measurement input in ADP mode. 3 TEMPin I Measurement input in Temperature mode. 4 CLAMPin I Current measurement input in CLAMP mode. 5 CHP I/O Positive connection for reference capacitor of high-speed A/D. 6 CHN I/O Negative connection for reference capacitor of high-speed A/D. 7 CIH O High-speed integrator output. Connect to integral capacitor. 8 BUFH O High-speed buffer output pin. Connect to integral resistor. 9 CAZH O High-speed auto-zero capacitor connection. 10 CLN I/O Negative connection for reference capacitor of high-resolution A/D. 11 CLP I/O Positive connection for reference capacitor of high- resolution A/D. 12 CIL O High-resolution integrator output. Connect to integral capacitor. (Metalized Polypropylene Film Capacitor type is recommended) 13 CAZL O High-resolution auto-zero capacitor connection. 14 BUFL O High-resolution buffer output pin. Connect to integral resistor 15 RAZ O Buffer output pin in AZ and ZI phase. 16 VRH O Output of band-gap voltage reference. Typically –1.23V. 17 DACO O Output of band-gap voltage reference. Typically –400 m V. 18 VR_CLAMP I Reference input voltage connection. Typically –400 mV. 19 VR_ADP I Reference input voltage connection. Typically –400mV. 20 OHMC4 O Filter capacitor connection for resistance mode. 21 OHMC3 O Filter capacitor connection for resistance mode. 22 OHMC2 O Filter capacitor connection for resistance mode. 23 OHMC1 O Filter capacitor connection for resistance mode. 24 OVSG O Sense low voltage for resistance/voltage measurement 25 OR1 O Reference resistor connection for 60.00/600.0Ω range 26 VR5 O Voltage measurement ÷10000 attenuator(1000V) 27 VR4 O Voltage measurement ÷1000 attenuator(600.0V) 28 VR3 O Voltage measurement ÷100 attenuator(60.00V) 29 VR2 O Voltage measurement ÷10 attenuator(6.000V) 30 ACVL I Rectified signal low input in ACV/ACA mode. Connect to negative output of external AC to DC converter. Rectified signal high input in ACV/ACA mode. Connect to positive output of 31 ACVH I external AC to DC converter. 32 ADI I Negative input of internal AC to DC OP Amp. 33 ADO O Output of internal AC to DC OP Amp. 34 TEST5 O Buffer output of OVSG. 35 SGND I Signal Ground input. 36 VR1 I Measurement Input. Connect to a precised 10MΩ resistor. V 2.2 3 2015/12/15 ES237 6000 Counts DMM Pin Description ( Continued ) Pin No Symbol Type Description 37 mVin I Measurement input in 600.0mV mode. 38 LPFout O Capacitor C1 connection for internal low-pass filter. 39 LPC1 O Capacitor C1 connection for internal low-pass filter. 40 LPC2 O Capacitor C2 connection for internal low-pass filter. 41 LPC3 O Capacitor C3 connection for internal low-pass filter. 42 CAN I/O Negative auto-zero capacitor connection for capacitor measurement. 43 CAP I/O Positive auto-zero capacitor connection for capacitor measurement. 44 R10K O Connect to a precised 10KΩ resister for capacitor measurement. 45 R1K O Connect to a precised 1KΩ resister for capacitor measurement. 46 OVX I Sense input for resistance / capacitance measurement. 47 OVH O Output connection for resistance measurement. 48 OVH1 O Output connection for resistance measurement. (Optional) 49 SLEEP O Sleep mode indicator, asserts low in SLEEP mode. 50 FREQ I Frequency counter input, offset V-/2 internally by the chip. 51 CALENP I Pulled to V- to enable the calibration scheme. 52 SDAP I/O 53 SCLP O Output to EEPROM 24LC02 clock. 54 BZOUT O Outputs a 2KHz audio frequency signal for driving piezoelectric buzzer 55 BKOUT O If BKLIT function is enabled, this pin will change from V- to V+. Once press BKLIT pin again within 300 sec, this pin will change back to V-. 56 ALARM1 O Short circuit indication output. 57 ALARM O HV signal detection in Voltage mode and EF mode indication output. 58 BP4 O LCD backplane 4. 59 BP3 O LCD backplane 3. 60 BP2 O LCD backplane 2. 61 BP1 O LCD backplane 1. 62 - 90 SEG29 - SEG01 O LCD segment line 01 – 29. 91 CESEL* I Voltage OL selection feature control pin. (1010V/610V) 92 SEL2* I Diode OL level and HV indication selection pin. 93 SEL1* I Set current mode OL level selection pin. (DMM or Clamp mode) 94 DIS* I Control warning buzzer output at LPF and HV mode 95 TSEL* I Input / Output from to EEPROM 24LC02 data. Temperature mode controls the automatic mode or manual mode and enable or disable input terminal symbol displayed on the LCD panel selection pin. Enable the auto range voltage mode to start from 600.0V or disable ADP input 96 VST* I terminal symbol displayed on the LCD panel selection pin. 97 APOSEL I 98 VBAR I Idle time selection for auto power off feature. In µA or mA modes, it is used to control the ‘µ’ or ‘m’ sign. Set to V- to enable clamp current mode. V 2.2 4 2015/12/15 ES237 6000 Counts DMM Pin Description ( Continued ) Pin No Symbol Type Description 99 RS232 I Assert low (V-) to make serial data output function not available. 100 OSC2 O Crystal oscillator output connection. 101 OSC1 I Crystal oscillator input connection. 102 RSOUT O Serial data output. 103 NC - Not connected 104 HZ I Pulse to V- to enable VAHZ mode or duty cycle measurement in Freq. mode. 105 MMX I Pulse to V- to enable MAX/MIN function. Pulse to V- to enable/disable Relative function or Zero function. Pulse to V- 106 REL I larger than one second to enable RS232 output. When RS232 output is enabled, the APO will be disabled automatically. 107 BKLIT I Back light function. Pulse low to set BKOUT pin output. 108 KEY I Pulse to V- to change mode. 109 HOLD I Pulse to V- to enable HOLD function. Pulse to V- larger than one second to enable Delayed Hold function. 110 RANGE I Pulse to V- to enable manual mode and manual range selection. 111 FC5 I Switch 5 for function selection. 112 FC4 I Switch 4 for function selection. 113 FC3 I Switch 3 for function selection. 114 FC2 I Switch 2 for function selection. 115 FC1 I Switch 1 for function selection. 116 SLACDC I Select initial DC/AC state. 117 CN O Negative capacitor connection for on-chip DC-DC converter. 118 CP O Positive capacitor connection for on-chip DC-DC converter. 119 LBAT9 I Multi-level low battery configuration input. Simple external resistor divider is required. 120 V- P Negative supply voltage. 121 V- P Negative supply voltage. 122 V+ O Output of on-chip DC-DC converter. 123 V+ O Output of on-chip DC-DC converter. 124 DGND P/G Digital ground. 125 AGND P/G Analog ground. 126 AGND P/G Analog ground. 127 NC - Not connected 128 NC - Not connected Note: Pin91-Pin96 are 4-level logic definition: (V+/DGND/Floating/V-), see section Operation mode V 2.2 5 2015/12/15 ES237 6000 Counts DMM Absolute Maximum Ratings Characteristic Rating Supply Voltage (V- to AGND) -4V Analog Input Voltage V- -0.6 to V+ +0.6 V+ V+ ≥ (AGND/DGND+0.5V) AGND/DGND AGND/DGND ≥ (V- -0.5V) Digital Input V- -0.6 to DGND +0.6 Power Dissipation. Flat Package 500mW Operating Temperature -20℃ to 70℃ Storage Temperature -45℃ to 125℃ Electrical Characteristics Parameter Power supply Symbol Voltage roll-over error VIDD ISS REV Voltage nonlinearity NLV Operating supply current In DCV mode Test Condition Normal operation In sleep mode 10MΩ input resistor Best case straight line CIL=MPR capacitor Min. Typ. Max Units 2.4 — — — -3.0 1.8 — — 3.3 2.5 10 ±0.1 V mA µA %F.S1 — — ±0.1 %F.S1 Zero input reading 10MΩ input resistor -000 000 +000 counts Band-gap reference voltage 100KΩ resistor between VRH and AGND -1.30 -1.23 -1.16 V — -3.0 — V -1.19 -1.08 -0.97 V -3.5V≤ V ≤-2.2V 3.0 3.1 3.2 V Between V- pin and HOLD, RANGE, KEY, FC1-FC5, BKLIT, — 1.2 — µA Between V- pin and RS232 — 11 — µA ±1% ±5% (No compensated) — — 40-400 400-2000 — — HZ F3dB = 1kHz — 1k — kHz F3dB = Full 100k — — kHz — 2.15 — — 1.82 — — 100 — ppm/℃ -2.52 -3 — — 2.52 3 % counts VREF Open circuit voltage for 600Ω measurement V-=3V Open circuit voltage for other Ω measurement Peak to peak backplane voltage Internal pull-high to 0V current AC frequency response at 6.000V range 3dB frequency for LPF mode Multi-level low battery detector Reference voltage temperature coefficient Capacitance measurement accuracy Vt1 Vt2 TCRF LBAT9 vs. V-20℃<T A<70℃ 6.0nF – 60mF V Note: 1. Full Scale. 2. When capacitance measurement (Clamp mode) is selected, the additional error 1% should be increased. V 2.2 6 2015/12/15 ES237 6000 Counts DMM Function Description 1. Operating Modes 1.1. Semi-auto calibration scheme ES237 includes DMM & Clamp-on meter features in single chip. DMM manufacturers need the calibration process in production. The traditional solution needs the variable resistors for calibration by manual adjustment. ES237 provide another calibration scheme and the most variable resistors could be ignored. When ES237 is at OFF-state, pull CALENP (pin 51) to V- to active the calibration scheme after re-power on. A digital controlled voltage output will be active from DACO. When semi-auto calibration scheme is active, use HOLD (or BKLIT) key to decrease voltage and use RANGE (or MMX) key to increase the voltage. Decrease the reference voltage means the counts on display will be increased. Increase the reference voltage means the counts on display will be decreased. The adjustment step is approximate one count. If coarse adjustment is required, push HOLD (or BKLIT) and RANGE (or MMX) larger than one second to speed up to approximate 10 counts per second. After calibration process is finished, push HOLD (or BKLIT) and RANGE (or MMX) less than 1 sec. simultaneously to save the digital control code to external EEPROM (24LC02). The semi-auto calibration scheme supports the following nine measurement modes. When CALENP pin is active, set the proper function switches or push KEY to choose the target measurement mode. When mode is selected, the LCD segment of Unit at related measurement will be blinking. Mode Default Range For CAL Remark Voltage Measurement 6.000V (DC/AC separated) mV Voltage Measurement 600.0mV (DC/AC separated) Accuracy of other ranges is guaranteed by external resistor. DC Current Measurement For Multimeter (uA/mA) 600.0μA or 6000μA ( 2 modes choose one for calibration ) 600.0μA or 6000μA (2 modes choose one for calibration ) AC Current Measurement For Multimeter (uA/mA) Auto 2 ranges choose one, proposed to use a large range to calibration. Auto 2 ranges separated for calibration is necessary. DC Current Measurement For Multimeter (A) 6A or 20A Auto 2 ranges choose one, proposed to use a large range to calibration. AC Current Measurement For Multimeter (A) 6A or 20A Auto 2 ranges individual calibration is necessary. DC Current Measurement For Clampmeter 600.0A or 6000A ( 6 modes choose one for calibration ) Auto 2 ranges choose one, proposed to use a large range to calibration. AC Current Measurement For Clampmeter 600.0A or 6000A ( 6 modes choose one for calibration ) Auto 2 ranges separated for calibration is necessary. Capacitor Measurement 60.00nF Temperature Measurement 600.0℃ ADP Measurement 6000 / 600.0 / 60.00 / 6.000 for Lower range in auto temperature measurement. 4 ranges separated for calibration. After calibration procedure is finished, set ES237 to OFF-state and set CALENP (pin51) to DGND or kept floating to return to normal mode operation after re-power on. V 2.2 7 2015/12/15 ES237 6000 Counts DMM 1.2. Voltage Measurement A re-configurable voltage divider automatically provides a suitable range in voltage measurement mode. 600.0mV range is independent and manual mode. It takes input signal from mVin pin. The following table summarizes the Full-Scale ranges in each configuration. Configuration Full Scale Range Divider Ratio Resister Connection Input Pin VR1 600.0mV 1 - mVin V.S. SGND VR2 6.000V 1/10 VR2 (1.111MΩ) VR1 V.S. SGND VR3 60.00V 1/100 VR3 (101KΩ) VR1 V.S. SGND VR4 600.0V 1/1000 VR4 (10KΩ) VR1 V.S. SGND VR5 1000V 1/10000 VR5 (1KΩ) VR1 V.S. SGND The VST pin is used to control the voltage start range from 6.000V or 600.0V, refer to the table. VST Initial state V+ DGND Floating V- 600.0V 6.000V 600.0V 6.000V The ES237 provide two types of the hazardous live voltage warning by different condition. SEL2 V+ DGND Floating DCV 35V 70V ACV 16V 33V V- When the voltage measured exceeds the level defined, the buzzer generates 2KHz beep and ALARM (pin 57) drive high output (V+ level) periodically. It can remind the user to notice the hazardous voltage. The buzzer sound warning could be cancelled by DIS (pin94). DIS V+ Buzzer V 2.2 DGND Disable Floating V- Enable 8 2015/12/15 ES237 6000 Counts DMM 1.2.1. OL Selection ES237 has a voltage OL selection feature archived by configuring the pin CESEL. In automatic voltage mode, ES237 will show OL when the voltage is exceed the overflow level. If CESEL is connected to V+, ES237 will have a 1010V overflow level in voltage mode. If CESEL connected to DGND, the overflow level will be set to 610V in DCV and ACV mode. The configuration of CESEL is listed below. For ACV/DCV voltage modes: CESEL OL level V+ DGND 1010V 610V Note: V-/Floating level is not available. 1.3. Low Pass Filter (LPF) Mode For ACA/ACV Mode ES237 provides a 3rd order low-pass filter to reduce the influence of high frequency noise. This LPF feature is available in ACV or ACA modes. Set FC5 to low in these modes, the KEY button is used to activate the LPF feature. Press KEY button for less than 1 second to select the 3dB bandwidth of LPF sequentially ( Full / 1kHz ) and the relative LCD symbol on LCD panel will be active also. The DIS (pin94) could enable/disable the Low Pass Filter feature available. DIS LPF V 2.2 V+ DGND Floating V- Disable Enable Disable Enable 9 2015/12/15 ES237 6000 Counts DMM 1.4. Current Measurement For Multi-meter ES237 has 3 automatic current measurement modes for multimeter. The following table summarizes the Full-Scale range of each mode. When ES237 operates in the current measurement modes for multi-meter, it takes high input from pin IVS, low input from pin SGND and reference voltage from calibration scheme. 1 VBAR Full Scale Input Terminal 1,1,0,1 1 600.0µA / 6000µA IVS V.S. SGND Automatic2 1,1,1,1 1 60.00mA / 600.0mA IVS V.S. SGND Automatic3 0,0,0,0 1 6.000A /10.00A2 IVS V.S. SGND Mode FC1~4 Automatic1 Note: 1. Connect VBAR to V- will disable the “µ2” / ”m2” symbol on LCD panel. 2. Connect SEL1 to V+(or Floated) or V- (or DGND) will set maximum readings of input for Automatic3 mode. SEL1 OL level V+ DGND Floating V- 10.00A 20.00A 10.00A 20.00A 1.5. Current Measurement For Clamp-meter ES237 has 2 automatic and 4 manual current measurement modes for Clampmeter. The following table summarizes the Full-Scale range of each mode. When ES237 operate in the automatic modes and the manual mode1~4, it takes high input from CLAMPin pin, low input from SGND and reference voltage from VR_CLAMP. Mode FC1~4 1 VBAR Full Scale Input Terminal 2 Automatic1 1,1,0,1 0 600.0A / 6000A CLAMPin V.S. SGND Automatic2 1,1,1,1 0 60.00A / 600.0A CLAMPin V.S. SGND Manual1 1,1,0,0 X 6.000A CLAMPin V.S. SGND Manual2 1,0,0,0 X 60.00A CLAMPin V.S. SGND Manual3 1,0,1,0 X 600.0A Manual4 1,0,0,1 CLAMPin V.S. SGND 2 X CLAMPin V.S. SGND 1000A or 2000A Note: 1. Connect VBAR to V- will disable the “µ2” / ”m2” symbol on LCD panel. 2. Connect SEL1 to DGND or V- will set maximum of input for Automatic1 & Manual4 modes. 3. In DC current modes for clamp-meter, ES237 provides Zero Function for offset removing. SEL1 V+ OL level V 2.2 DGND 1000A Floating V- 2000A 10 2015/12/15 ES237 6000 Counts DMM 1.6. SCAN RSDC measurement ES237 provide the smart auto check mode for the DUT type. It could scan the four types of device Resistor / Shorted / Diode / Capacitor. Push KEY to change to individual function is available. It could increase the measurement ranges. The following table summarizes the detective range for the smart scan RSDC mode. Mode FC1~4 SLACDC Available scanning range R: ~ 6MΩ (Parasitic capacitance < 100pF) Scan RSDC 1,1,1,0 0 S: < 30Ω buzzer ON D: forward/reverse diode direction C: ~ 600uF (Minimum 500pF) 1.7. 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. V 2.2 Configuration Full Scale Range Relative Resistor Equivalent value OR0 60.00Ω OR1 100Ω OR1 600.0Ω OR1 100Ω OR2 6.000KΩ VR5 1KΩ OR3 60.00KΩ VR4 || VR1 10KΩ OR4 600.0KΩ VR3 || VR1 100KΩ OR5 6.000MΩ VR2 || VR1 1MΩ OR6 60.00MΩ VR1 10MΩ 11 2015/12/15 ES237 6000 Counts DMM 1.8. Capacitance Measurement The following table summarizes the eight ranges of capacitance measurement mode. Configuration1 Full Scale Range Relative Resistor Measurement Period C1 3 6.000nF Ratio to C2 0.36 sec C2 2 60.00nF CAL 0.36 sec C3 600.0nF Ratio to C2 1.15 sec C4 6.000uF Ratio to C2 1.15 sec C5 60.00uF R10K 0.33 sec C6 600.0uF R10K 3.3 sec(max) C7 6.000mF R1K 1.32 sec(max) C8 60.00mF R1K 13.2 sec(max) Note: 1. 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 main-display shows dIS.C. Discharging through the chip is quite slow. We recommend users to discharge the capacitor with some other apparatus. 2. The C2 range is calibrated in calibration scheme. 3. The C1 range residual offset could be compensated by the small capacitors near to OVH pin. 1.9. 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 and ALARM1 (pin 56) drive high output (V+ level) whenever the reading is less than 30Ω. The ES237 built in a high speed short detection circuit and the detection could be less than 10ms. V 2.2 12 2015/12/15 ES237 6000 Counts DMM 1.10. 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 and ALARM1 (pin 56) drive high output (V+ level) whenever the reading is less than 30mV. If the test circuit is open or the voltage drop between the two ports of the diode under test is larger than 2V or 2.5V (depends on SEL2 pin level), the LCD panel will show “OL”. SEL2 OL V+ DGND Floating V- 2.500V 2.000V 2.500V 2.000V The ES237 also support a LED forward voltage measurement mode. It is necessary to use external source to achieve the measurement. The following table & diagram summarizes the diode & LED measurement mode. Mode SLACDC FC1~4 SEL2 Full Scale Input Terminal LED 1 0,0,1,0 V+ or FLOAT 3.500V VR1 V.S. SGND External Source Internal Source V+ V OVH ES235 / 236 / 238 / 239 PTC PTC LED Mode Diode Mode 10M LED R 1.111M OVSG V 2.2 13 2015/12/15 ES237 6000 Counts DMM 1.11. Frequency Counter The time base of the frequency counter is derived from an external crystal oscillator by 4,000,000 Tcounter = Fosc Where Fosc is the frequency of the crystal oscillator. Thus, the counter has a 1-second time base when a 4MHz oscillator is used. The frequency counter can select the proper range automatically or manually. Auto-range operation extends over six decades, from 600.0Hz to 60.00MHz. The following table summarizes the Full-Scale range of the frequency counter. Range Full Scale FR1 600.0Hz FR2 6.000KHz FR3 60.00KHz FR4 600.0KHz FR5 6.000MHz FR6 60.00MHz *If input frequency is less than 1.0Hz, ES237 will show 0.0Hz 1.12. Duty Cycle Measurement When frequency mode is selected, push HZ key to enter duty cycle measurement. The duty cycle mode range is within 5.0% to 95.0% (< 10kHz@3Vpp). The minimum resolution is 0.1%. If the source frequency duty cycle is smaller than 5.0%, the UL will be shown on the LCD display. If the duty cycle is larger than 95.0%, the OL will be shown on the LCD. When the frequency is zero, the duty cycle display will be 0.0% or “UL” shown. V 2.2 14 2015/12/15 ES237 6000 Counts DMM 1.13. Electrical field detection mode ES237 supports a non-contact AC voltage measurement, which is called electric field measurement also. The ADC input is configured from ADP pin vs. SGND. When no or less electric field is detected, the LCD display shows “EF”. If the electric field is detected, the strength will be showed on the LCD display by “-“ not digits type. Level 1(equivalent to 12.5% full scale of ADC) is “-“ and the level 4(equivalent to 100% full scale of ADC) is “----“. Additional beeper (BUZOUT pin) and LED alarm (ALARM pin) will be output from ES237. The frequency of buzzer and LED alarm depends on the strength of electric field also. The Faster beeper means the stronger electric field (AC voltage) is sensed. Mode FC1~4 SLACDC Full Scale Input Terminal EF 1,1,1,0 1 - ADP V.S. SGND EF test circuit 100k EFin+ ADP 100M EFin- SGND AGND -400mV VRADP 1.14. Temperature Measurement mode Temperature measurement mode takes input signal from TEMPin pin. The ES237 has ºC to ºF scale translation circuit and standard K-type thermocouple reference table is built-in. External cold-junction compensation circuit is still necessary. In temperature measurement mode, there is automatic mode and manual mode. The TSEL pin (pin95) is used to control the automatic mode (0.1OC/1OC resolution) or manual mode (0.1OC resolution) selection. It also could enable or disable display of input terminal symbol on the LCD panel (SEG28). Manual range Auto Range ºC range -200.0 ºC ~ 600.0 ºC -200.0 ºC ~ 600.0 ºC / -200 ºC ~ 1350 ºC ºF range -328.0 ºF ~ 999.9 ºF -328.0 ºF ~ 999.9 ºF / -328 ºF ~ 2462 ºF The following table summarizes the operation of TSEL pin: TSEL V 2.2 Range select V+ Manual range DGND Auto range Floating Manual range VAuto range LCD SEG28 Display Symbol ON Display Symbol ON Display Symbol OFF Display Symbol OFF 15 2015/12/15 ES237 6000 Counts DMM Temperature mode circuit example: 1.15. ADP ES237 provides 4 manual range ADP measurement modes for user define. The ADP pin is auxiliary input terminal for ADC of ES237. The full scale for ADP mode is 600.0mV. If FC5=0, the minus sign will not be shown on LCD segment. Mode FC1~4 SLACDC Full Scale Input Terminal ADP0 0,0,1,1 1 6000 ADP V.S. SGND ADP1 0,0,0,1 1 600.0 ADP V.S. SGND ADP2 0,1,1,1 1 60.00 ADP V.S. SGND ADP3 1 1 6.000 ADP V.S. SGND 0,0,1,0 Note: 1. If SEL2 pin is set to V+ or kept floating, the ADP3 mode will be disabled and change to LED mode. The VST pin (pin96) could be used to enable or disable input terminal symbol displayed on LCD panel for ADP mode. VST V+ LCD SEG28 V 2.2 DGND Display Symbol ON 16 Floating V- Display Symbol OFF 2015/12/15 ES237 6000 Counts DMM 1.16. Auto Power Off And Idle Time Selection ES237 has a default auto power off function. If the meter is idle for more than the given idle time duration, the chip automatically turns the power off. The idle time to trigger the auto power off function is determined by APOSEL pin. If APOSEL is connected to V-, the idle time will be set to 30 minutes. If pin APOSEL is floating, the Idle Time will be set to 15 minutes. When APO is occurred, the state of the meter is reserved. The APO symbol on the LCD panel indicates whether the auto power off is enabled or not. In some cases, user might want to disable Auto power off. There are two ways to disable this feature as following: 1. Power on the meter when any of the push functions, except for HOLD, is pressed down. 2. In addition, when RS232 output is active, the auto power off function is also disabled automatically. Note: Powering on the meter while pressing HOLD and lasts 2 seconds turns on all LCD segments until HOLD is pressed again. 1.17. Sleep The meter enters sleep mode after auto power off. The SLEEP pin asserts low (V-) in the sleep mode, and asserts high (V+, not 0V) after re-power on. 1.18. Re-Power On After auto power-off, pushing any of the push function or changing the rotary mode can turn on the meter again. If the meter is re-powered on by changing the rotary mode, 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. 1.19. Hazardous Voltage Indication The ES237 could provide the AC/DC hazardous voltage indication for voltage/resistor/capacitor/diode modes. Of course, the indication could support LCD symbol /LED /Buzzer driving simultaneously. Especially ES237 could detect the AC voltage in DCV mode and detects the DC voltage in ACV mode. It means if not proper AC or DC voltage signal exists on the DUT when DCV or ACV measurement mode is set, the HV indication will be active. V 2.2 17 2015/12/15 ES237 6000 Counts DMM HV indication criterion Function / Range DC voltage (typ.) AC voltage (typ.) AC mV > +3V OL AC 6V > +20V OL AC 60V – 1000V > +100V Depends on SEL2 DC mV OL > 3Vrms (40-1kHz) DC 6V OL > 20Vrms (40-1kHz) DC 60V-1000V Depends on SEL2 > 90Vrms (40-1kHz) Res/Cap/Diode modes > +10V > 10Vrms (40-1kHz) Note: If AC+DC signal is applied, the voltage criterion will be changed. 1.20. Multi-level Low Battery Voltage Detection ES237 provides a voltage detection input (pin 121: LBAT9) for multi-level low battery application. There are two internal voltage reference Vt1 & Vt2 for comparing with LBAT9. If LBAT9 is larger than Vt1, the LCD segment of SLB1 – SLB3 will active always. This status implies Full battery. When LBAT9 is less than Vt1 but larger than Vt2, the LCD segment of SLB1 will disappear and this status implies Half battery. When LBAT9 is less than Vt2, the LCD segment of SLB2 will disappear and this status implies Low battery. When the Low battery status lasts for 10 seconds, the LCD segment of SLB3 will be blinking. When the SLB3 is blinking for 20 seconds, the operation of meter will be inhibited and LCD panel will show “ Lo.bt”. In this case, it is suggested to replace a new battery immediately. After “Lo.bt” appears and lasts for 60 seconds, ES237 will enter to auto power off mode. Full battery Half battery Low battery condition > 30s Operation not allowed Low battery blinking AUTO AUTO AUTO AUTO DC DC DC DC 1.8 0 0 V 1.8 0 0 Low battery test circuit (a) V 1.8 0 0 L o.b t Low battery test circuit (b) 3V 9V BA 120K TTE BA LBAT9 0.1u 470K 910K TTE AGND V- LBAT9 0.1u 300K 0V V 2.2 V AGND V- 0V 18 2015/12/15 ES237 6000 Counts DMM 2. Measurement Mode Switching Measurement mode depends on the logic level of SLACDC, FC1, FC2, FC3, FC4, FC5 and KEY selection. When FC5 is high, the measurement mode list is shown below: SLACDC FC1 FC2 FC3 FC4 0 1 0 1 1 0 0 1 1 1 1 0 1 1 1 0 0 0 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 23 23 Mode KEY selection DC Voltage Measurement DCV ↔ ACV Auto DC Current Measurement(µA) DCA ↔ ACA Auto DC Current Measurement(mA) DCA ↔ ACA 23 Auto DC Current Measurement(A) DCA ↔ ACA Scan RSDC Ω Continuity Diode Cap Scan 0 3 Manual DC 6.000A DCA ↔ ACA 0 3 DCA ↔ ACA DCA ↔ ACA Manual DC 60.00A 0 1 0 1 0 3 0 1 0 0 1 3 0 0 0 1 0 0 0 0 0 0 Manual DC 600.0A Manual DC 6000A DCA ↔ ACA 1 Resistance Measurement Ω ↔ Continuity 0 1 Continuity Check Continuity ↔ Diode 1 1 1 Resistance Measurement Ω Continuity Diode 0 0 1 0 Frequency Measurement ---- 0 0 1 1 0 Capacitance Measurement ---- 0 0 1 0 0 Auto Temperature Measurement ℃↔ ℉ 0 0 1 0 1 DCmV DCmV ↔ ACmV 1 1 0 1 1 AC Voltage Measurement ACV ↔ DCV 1 1 1 1 1 1 0 1 1 1 1 0 0 0 0 1 1 1 1 0 1 1 1 1 1 0 0 0 23 23 Auto AC Current Measurement(µA) ACA ↔ DCA Auto AC Current Measurement(mA) ACA ↔ DCA 23 Auto AC Current Measurement(A) EF mode ---- 0 3 Manual AC 6.000A ACA ↔ DCA 0 3 ACA ↔ DCA ACA ↔ DCA Manual AC 60.00A 1 1 0 1 0 3 1 1 0 0 1 3 1 1 1 0 0 0 0 0 1 1 0 1 ACA ↔ DCA 1 1 1 Manual AC 600.0A Manual AC 6000A 1 1 1 1 ACA ↔ DCA ADP0 ( 6000 ) ---- ADP1 ( 600.0 ) ---- ADP2 ( 60.00 ) ---- ADP3 ( 6.000 ) Set to LED mode if SEL2 is kept float 1 0 0 1 0 1 0 1 1 0 Capacitance Measurement (Clamp) ---- 1 0 1 0 0 Auto Temperature Measurement ℉↔℃ 1 0 1 0 1 ACmV ACmV ↔ DCmV Note: 1. When FC5 is high, the ADP0, ADP1, ADP2 and ADP3 modes can display minus sign. 2. These modes could be designed for multimeter current modes, please refer to section 1.4. 3. These modes could be designed for clampmeter current modes, please refer to section 1.5. . V 2.2 19 2015/12/15 ES237 6000 Counts DMM Measurement Mode Switching (Continued) Measurement mode depends on the logic level of SLACDC, FC1, FC2, FC3, FC4, FC5 and KEY selection. When FC5 is low, the KEY function is disabled in most modes. The measurement mode list is shown below: SLACDC FC1 FC2 FC3 FC4 0 1 0 1 1 0 0 1 1 1 1 0 1 1 1 0 0 0 0 0 0 1 1 1 0 23 23 Mode KEY selection & Remaks DC Voltage Measurement ---- Auto DC Current Measurement(µA) ---- Auto DC Current Measurement(mA) ---- 23 Auto DC Current Measurement(A) ---- Scan RSDC Ω Continuity Diode Cap Scan Manual DC 6.000A ---- 0 1 1 0 0 3 0 1 0 0 0 3 ---- 0 3 ---- 3 0 1 0 1 Manual DC 60.00A Manual DC 600.0A Manual DC 6000A ---- 1 Resistance Measurement ---- 0 1 Continuity Check ---- 1 1 1 Diode Measurement ---- 0 0 1 0 Frequency Measurement ---- 0 0 1 1 0 Capacitance Measurement ---- 0 0 1 0 0 Auto Temperature Measurement ℃ 0 0 1 0 1 DCmV ---- 1 1 0 1 1 AC Voltage Measurement LPF Full1K 0 1 0 0 1 0 0 0 1 0 0 0 0 0 0 1 1 1 1 1 1 0 1 1 1 1 0 0 0 0 1 1 1 1 0 23 23 Auto AC Current Measurement(µA) LPF Full1K Auto AC Current Measurement(mA) LPF Full1K 23 Auto AC Current Measurement(A) LPF Full1K EF mode ---- Manual AC 6.000A LPF Full1K 1 1 1 0 0 3 1 1 0 0 0 3 LPF Full1K 0 3 LPF Full1K 1 3 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 1 0 1 0 1 1 1 1 Manual AC 60.00A Manual AC 600.0A Manual AC 6000A 1 1 1 1 LPF Full1K ADP0 ( 6000 ) ---- ADP1 ( 600.0 ) ---- ADP2 ( 60.00 ) ---- ADP3 ( 6.000 ) Set to LED mode if SEL2 is kept float 1 0 0 1 0 1 0 1 1 0 Capacitance Measurement (Clamp) ---- 1 0 1 0 0 Auto Temperature Measurement ℉ 1 0 1 0 1 ACmV LPF Full1K Note: 1. When FC5 is low, the ADP0, ADP1, ADP2 and ADP3 modes can’t display minus sign. 2. These modes could be designed for multi-meter current modes, please refer to section 1.4. 3. These modes could be designed for clamp-meter current modes, please refer to section 1.5. V 2.2 20 2015/12/15 ES237 6000 Counts DMM 3. Push Function All the enabled push functions will be reset when the measurement mode is changed when FC1-FC5 modes are changed. The following table lists the available function versus every measurement mode. HZ MMX REL/RS2325 BKLIT KEY HOLD RANGE Voltage mode AC O O O O O O mV mode AC O O O O O X Current Mode for Multimeter AC O O O O O O Current Mode for Clampmeter AC O O3 O O O X Resistance X O O O O O O Continuity X O O O O O X Diode mode X O O O O O X Frequency O X O O X O O Capacitance X O O O X O O Temperature X O O O O O O4 Scan RSDC X X O O O O X EF Mode X X O O X X X ADP mode X O O O X O X 1 2 Note: Include automatic μA, automatic mA and manual A modes, please refer to section 1.4. 1 2 Include 2 automatic modes and 4 manual modes, please refer to section 1.5. 3 When clamp-meter DCA mode is selected, the REL function will be changed to ZERO function operation automatically. 4 Only auto range temperature mode is available. 5 When RS232 (pin99) is pulled to V-, push REL key and lasts for 2 seconds will active the UART output. V 2.2 21 2015/12/15 ES237 6000 Counts DMM 3.1. Range Push RANGE1 key to switch from automatic to manual mode, and while in manual mode, changes the full-scale range. The following figure shows the state transition. 1 push < 1 sec Manual Mode Automatic Mode 1 push > 1 sec Range up 1 push < 1 sec Measurement Mode Auto Manual Control Range Initial Range V VR2 – VR5 VRi → VRi + 1, VR5 → VR2 6.000V – 1000V 6.000V2 Auto µA R1 – R2 R1 → R2, R2 → R1 600.0µA – 6000µA 600.0µA Auto mA R1－R2 R1 → R2 R2 → R1 60.00mA – 600.0mA 60.00mA Auto A R1－R2 R1 → R2 R2 → R1 6.000A – 10.00A 6.000A Auto 60A/600A (clamp) R1－R2 R1 → R2 R2 → R1 60.00A – 600.0A 60.00A Auto 600A/6000A (clamp) R1－R2 R1 → R2 R2 → R1 600.0A – 6000A 600.0A Capacitance C1 – C8 Ci → Ci + 1, C8 → C1 6.000nF– 60.00mF 6.000nF Capacitance (Clamp) C1 – C8 Ci → Ci + 1, C8 → C1 6.000nF– 60.00mF 6.000nF Ω OR0 – OR6 ORi → ORi + 1, OR6 → OR0 60.00Ω – 60.00MΩ 60.00Ω Temp T1-T2 T1T2 T2T1 600.0oC~1350oC 600.0oC Frequency FR1 – FR7 FRi → FRi + 1 FR7 → FR1 600.0Hz – 60.00MHz 600.0Hz Note: 1. Pushing RANGE resets all existing special modes except for VAHZ mode. 2. Initial range of voltage mode depends on VST pin configuration V 2.2 22 2015/12/15 ES237 6000 Counts DMM 3.2. HOLD and Delayed Hold Feature HOLD mode makes the meter stop updating the LCD panel. This mode can be nested in most of the special modes. Enabling HOLD function in automatic mode makes the meter switch to manual mode, but the Full-Scale range remains the same. ES237 provides a Delay HOLD feature. To activate Delay HOLD feature, press down the HOLD bottom and last for 2 seconds. The meter will delay for 6 seconds, than enters HOLD mode. In the 6-secnod delayed time, the HOLD symbol on LCD panel will blink. HOLD function and the delayed state can be cancelled by changing the measurement mode, pressing RANGE, or push HOLD again. Push > 2s 6sec past Normal mode Push < 2s HOLD mode (Auto/Manual) Push < 2s (Manual) Delay State (Auto/Manual) Push > 2s Push < 2s 3.3. KEY See Section “Measurement Mode Switching” for the function of this pin. 3.4. REL + HOLD In REL mode, the LCD panel displays DN+K - DN, where N = 1, 2, 3, … , DN is the last value before REL key is pushed, and DN+K is the current value. The meter returns to normal operation if REL is pressed again. Pressing HOLD in REL mode makes the meter stop updating the LCD panel. push REL Original State (Auto/Manual) push HOLD 〝REL〞active. 〝REL〞and〝H〞active. The relative value Hold the relative value push REL push HOLD Note: 1. It’s possible that relative value (DN+K - DN) exceeds 6,000 or -6,000 counts. The LCD shows OL in REL mode only if DN or DN+K is more than 6,000 counts. V 2.2 23 2015/12/15 ES237 6000 Counts DMM 3.5. Max/Min + HOLD The meter displays the maximum or minimum value of the input in Max/Min mode. When MMX key is pressed for the first time, the meter displays the maximum value. The meter displays the minimum value, when it is pressed again. When MMX key is pressed for the third time, the meter displays current value. The meter returns to normal operation if MMX is pressed and held for longer than one second. Pressing HOLD 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 min value current value max value 1push<1s Push HOLD 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 3.6. Relative + Max/Min + HOLD Max/Min mode can be nested in REL mode. The meter displays the maximum or minimum value relative to the reference when MMX is pressed in REL mode. Pressing HOLD under REL + Max/Min makes the meter stop updating the LCD panel. Original State (Auto/Manual) Push REL Push REL 〝REL〞active. The relative value Push MMX > 1s Push MMX 〝REL〞and〝Max〞active. 〝REL〞and〝Min〞active. 〝REL〞 〝Max〞 〝Min〞blink. Maximum rel. value Minimum rel. value Current rel. value Push MMX Push MMX Push HOLD Push HOLD 〝REL〞,〝Max〞, 〝H〞active. Hold max. rel. value 〝Min〞, 〝H〞active. Hold 〝REL〞 〝Max〞 , 〝Min〞 , , 〝H〞blink. Hold the 〝REL〞, Push MMX min. rel. value Push HOLD Push MMX current rel. value Push MMX V 2.2 24 2015/12/15 ES237 6000 Counts DMM 3.7. ZERO Function In manual DC 6.000A, 60.00A, 600.0A and 6000A, auto DC 60.00A/600.0A, and auto DC 600.0A/6000A (please refer to section 1.5) mesurement modes, ES237 provides ZERO function to remove the residual current value. Push REL key less than one second to enter ZERO mode. In ZERO mode, the LCD panel displays DN+K - DN, where N = 1, 2, 3, … , DN is the last conversion value before REL key is pushed, and DN+K is the current conversion value. If REL key is pushed again in ZERO mode, the meter will refresh the DN value and displays the DN+K - DN again. The meter returns to normal operation if REL key is pressed and held for longer than one second. Pressing HOLD in ZERO mode makes the meter stop updating the LCD panel. In 2-range auto DCA modes for clampmeter (600.0A/6000A or 60.00A/600.0A), the system will stay in automatic mode, even if the ZERO function is activated. In other words, It could achieve real automatic operation. In automatic mode, ZERO function could not be entered from higher range, but it could be still activated if current range is lower one. This is because most residual current value is so small that the range could not be higher one in automatic mode. When enter ZERO mode from lower range, the system will store the nonzero counts (residual current value). If the range goes up to higher one automatically, the nonzero counts will be divided by ten. So this function will still work well in automatic modes. State diagram for ZEROmode : Original State Press Zero Press Zero > 1s ‘Zero’ Active Press Zero < 1s Show DN+K - DN State diagram for ZERO + HOLD mode : Original State Press Zero Press Zero > 1s ‘Zero’ Active Show DN+K - DN Press Zero < 1s Press Hold ‘Zero’ ‘Hold’ Active Stop LCD upgrading V 2.2 25 2015/12/15 ES237 6000 Counts DMM State diagram for ZERO + Max/Min + HOLD mode : Original State (Auto/Manual) Push REL Push REL > 1s ‘Zero’ Active Push REL < 1s Show DN+K - DN Push MMX > 1s Push MMX ‘Zero’ ‘Max’ Active ‘Zero’ ‘Min’ Active 〝Zero〞 〝Max〞 〝Min〞blink. Show Max. DN+K - DN Show Min. DN+K - DN Current DN+K - DN Push MMX Push MMX Push HOLD Push HOLD Push HOLD 〝Zero〞 〝Max〞 , 〝Min〞 , , ‘Zero’ ‘Max’ ‘Hold’ ‘Zero’ ‘Min’ ‘Hold’ 〝H〞blink. Hold the active Hold Max. active Hold Min. Push MMX Push MMX DN+K - DN Value DN+K - DN Value current DN+K - DN Push MMX 3.8. VAHZ Function When voltage or current measurement mode is selected, the VAHz funtion is available. Push HZ key to select this frequency measurement mode. The frequency is measured by auto ranging. The maximum frequency range is 60KHz. The sensitivity of signal input is 5% full scale of signal in voltage or current mode typically. V 2.2 Configuration RANGE FR1 600.0Hz FR2 6.000KHz FR3 60.00KHz 26 2015/12/15 ES237 6000 Counts DMM 4. Serial Data Output The RS232 function will be activated if press down the REL key and last for 2 seconds, RS232 symbol will be shown on the LCD display. The serial data sent to SDO pin periodically at every A/D conversion cycle by 15 times per second. The data format complies with 8Bits transmission code with a baud rate of 9600. The host can use RS232 interface to read the data. A single data packet includes a start bit (always 0), 8 data bits with no parity check bit, and a stop bit (always 1). The high and low voltage levels correspond to DGND and V- respectively. SDO remains at 1 (high) when it is inactive. Hence the start bit (0) could be used as the triggering signal to begin the reading process. The following figure shows the data format of a single packet. Single packet 0V -3V 0 D7 D6 MSB D4 D3 D2 D1 D0 D5 1 LSB One data block consists of 17 packets. The following figure shows the format of a data block. The Header and Device code leads the whole packets. The range packet indicates the decimal point position on LCD panel of meter. Main_Digit1-3 consists of the readings on the LCD panel. The function packet indicates the measurement mode of the meter. Status1-4, Unit and Bargraph give the other status of the meter. CR and LF are delimiters used to separate the blocks. V 2.2 27 2015/12/15 ES237 6000 Counts DMM All packets D7 D0 0 1 0 1 0 Device Header Range 1 0 1 Main_Digit1 0 1 0 1 0 1 0 1 Main_Digit2 Main_Digit3 Function1 Function2 0 1 0 1 0 0 Status2 Status1 Function3 1 0 1 0 Status4 0 1 0 Status3 1 0 Bargraph Unit 1 1 CR 1 LF The meter always outputs the current value shown on LCD screen to the serial port. The detailed data format of each packet is listed below. D0 D1 D2 D3 D4 D5 D6 D7 a01 0 0 0 0 1 1 1 1 Header a02 1 0 0 0 0 0 0 1 Device a03 X X X X M_DP1 M_DP2 M_DP3 X Range a04 M_SIGN X X X X X X X Main_Digit1 a05 Digit33 Digit32 Digit31 Digit30 Digit23 Digit22 Digit21 Digit20 Main_Digit2 a06 Digit13 Digit12 Digit11 Digit10 Digit03 Digit02 Digit01 Digit00 Main_Digit3 a07 V A Ohm Continuity Diode Capacitance Hz Duty Function1 a08 VAHZ ℃ ℉ X EFmode SCAN Clamp LED Function2 a09 ADP0 ADP1 ADP2 ADP3 X X X X Function3 a10 AUTO MANU AC DC OL UL X X Status1 a11 SLB3 SLB2 SLB1 LBAT30s BW_full X BW1K HOLD Status2 a12 REL ZERO MAX MIN CURRENT X X X Status3 a13 Danger OPEN SHORT DISCH X X X X Status4 a14 Mega Kilo X Mili X Micro X Nano Unit a15 B_SIGN X B<06> B<05> B<04> B<03> B<02> B<01> Bargraph a16 0 0 0 0 1 1 0 1 CR a17 0 0 0 0 1 0 1 0 LF Note： 1. X undefind. 2. Whole packet is shown by LSB first. V 2.2 28 2015/12/15 ES237 6000 Counts DMM 4.1. RANGE This packet indicates range state of the meter. The M_DP1 – M_DP3 corresponding DP1 – DP3 of LCD segment (see section 5). In DCV 6.000V range, this a03 packet will set xxxx001x. If change to 60.00V the packet will be xxxx010x. a03 D0 D1 D2 D3 D4 D5 D6 D7 X X X X M_DP1 M_DP2 M_DP3 X 4.2. Main_Digit1 –Main_Digit3 Main_Digit1 – Main_Digit3 is the readings of measurement result shown on LCD panel. DigitN3 – DigitN0 consist of 4-bit BCD code. The M_SIGN is the sign bit of readings. D0 D1 D2 D3 D4 D5 D6 D7 a04 M_SIGN X X X X X X X a05 Digit33 Digit32 Digit31 Digit30 Digit23 Digit22 Digit21 Digit20 a06 Digit13 Digit12 Digit11 Digit10 Digit03 Digit02 Digit01 Digit00 4.3. FUNCTION The packets of a07-a09 indicate the measurement mode of the meter. The following table summarizes the transmitted bit for each mode. Note that the encoding of this packet is different from the encoding of FC1-FC5 switch. For example, if the meter operates in Voltage mode, this a07 packet is 10000000. If VAHZ key is pushed to VAHZ mode, the a08 will be 10000000 also. D0 D1 D2 D3 D4 D5 D6 D7 a07 V A Ohm Continuity Diode Capacitance Hz Duty a08 VAHZ ℃ ℉ X EFmode SCAN Clamp LED a09 ADP0 ADP1 ADP2 ADP3 X X X X 4.4. STATUS The a10-a13 packets indicate the whole status when ES237 is in normal operation. For example, if meter is operated at ACV / MANU range, then a10 packet will set 011000xx. The format of the four packets are shown below. V 2.2 D0 D1 D2 D3 D4 D5 D6 D7 a10 AUTO MANU AC DC OL UL X X a11 SLB3 SLB2 SLB1 LBAT30s BW_full X BW1K HOLD a12 REL ZERO MAX MIN CURRENT X X X a13 Danger OPEN SHORT DISCH X X X X 29 2015/12/15 ES237 6000 Counts DMM AUTO: When auto range is selected. MANU: When manual mode is selected. AC: When AC mode is selected. DC: When DC mode is selected. OL: When ‘OL’ is displayed on LCD. UL: When’UL’ is displayed on LCD. SLB3/SLB2/SLB1: When low battery segment is shown on LCD. LBAT30s: When ‘Lobt’ is shown on LCD. BW1k/full: Indication of low-pass-filter 3dB bandwidth. HOLD: When Data HOLD mode is active. REL: When Relative mode is active. ZERO: When Zero mode is active. MAX/MIN/CURRENT: When MAX/MIN mode is active. If CURRENT=1 means MAX/MIN symbol is blinking on LCD. Clamp: When clamp current mode is selected. Danger: Hazard voltage warning symbol is active on LCD. OPEN: Open state is detected on Scan mode. SHORT: Short circuit is detected on Continuity or diode mode. DISC: The ‘DisC’ is shown on LCD. It means the DUT is necessary to be discharged on Cap mode. 4.5. Unit This packet indicates the measurement unit of the LCD display. a14 D0 D1 D2 D3 D4 D5 D6 D7 Mega Kilo X Mili X Micro X Nano 4.6. Bargraph The a15 packet is the readings of bar-graph shown on LCD panel. B06 – B01 consist of 6-bit unsigned binary code. The B_SIGN is the sign bit of bar-graph. The result is necessary to be divided by 2 to match the bar-graph of LCD panel. The format of this packet is shown below. a15 D0 D1 D2 D3 D4 D5 D6 D7 B_SIGN X B06 B05 B04 B03 B02 B01 4.7. CR Carriage return: The transmitted code is 00001101. 4.8. LF Line feed: The transmitted code is 00001010. V 2.2 30 2015/12/15 ES237 6000 Counts DMM 5. 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 generates a 2KHz beep which 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 V 2.2 31 2015/12/15 ES237 6000 Counts DMM 5.1. LCD Panel S01 BP1 SLB1 S02 APO S03 S04 S05 SCAN AUTO S06 S07 S08 S09 S10 S11 S12 S13 S14 S15 4F 4A 4B HOLD 3F 3A 3B Buz 2F 2A BP2 SLB2 RS232 MAN AC Minus 4E 4G 4C DP3 3E 3G 3C DP2 2E 2G BP3 SLB3 Danger bar0 DC bar3 bar5 4D bar8 bar10 bar12 3D bar15 bar17 bar19 2D BP4 bar21 bar- bar1 bar2 bar4 bar6 bar7 bar9 bar11 bar13 bar14 bar16 bar18 bar20 S16 S17 S18 S19 S20 S21 S22 S23 S24 S25 S26 S27 S28 S29 BP1 2B Diode 1F 1A 1B REL LED μ2 M n Vin ADP0 BP2 2C DP1 1E 1G 1C MAX ℃ m2 K μ1 COM ADP1 BP3 bar22 bar24 bar26 1D bar29 MIN ℉ V Ω m1 mAin ADP2 BP4 bar23 bar25 bar27 bar28 bar30 A Hz F % Full 1K Ain ADP3 LCD Backplane Waveform V- +3.1 BP1 VV- +3.1 BP2 VV- +3.1 BP3 VV- +3.1 BP4 V- V 2.2 32 2015/12/15 ES237 6000 Counts DMM 5.2. LCD Display On Condition LCD Annunciator Condition V In voltage measurement mode, and diode measurement mode. A In current measurement mode. Ω In resistance measurement mode, and continuity mode. F In capacitance measurement mode. In continuity check mode. In diode mode. % In duty cycle measurement. Hz In frequency mode. ADP1 When ADP1 mode is active. ADP2 When ADP2 mode is active. ADP3 When ADP3 mode is active. ADP4 When ADP4 mode is active. DC In DC voltage or DC current mode. AC In AC voltage or AC current mode. AUTO When automatic full scale range selection is enabled. MANU In manual mode. HOLD When HOLD function is enabled. When Relative function is enabled. MAX When MAX function is enabled. MIN When MIN function is enabled. SCAN When smart (resistance, continuity, diode, capacitance auto check mode) is active. m1 In capacitor measurement mode and the full scale range is in the order of mF. µ1 In capacitor measurement mode and the full scale range is in the order of uF. n In capacitor measurement mode and the full scale range is in the order of nF. m2 In voltage or current measurement mode and the full scale range is in the order of 10-3. µ2 In current measurement mode and the full scale range id in the order of uA. M In resistance measurement mode and the full scale range is in the order of MΩ. K In resistance measurement mode and the full scale range is in the order of KΩ. ℃ In temperature measurement mode and when the unit is ℃ . ℉ In temperature measurement mode and when the unit is ℉ . When the reading is exceeding default hazardous live voltage or OL in DCV or ACV, the HV warning symbol will be display. APO When auto power off function is enabled. SLB1 When voltage (ref. to V-) of LBAT9 pin is less than Vt1, SLB1 will disappear. SLB2 When voltage (ref. to V-) of LBAT9 pin is less than Vt2, SLB2 will disappear. SLB3 When SLB2 disappears for 8 seconds, SLB3 will be blinking. RS232 When RS232 output is enabled. TEST V 2.2 When LED measurement function is enabled. 33 2015/12/15 ES237 6000 Counts DMM 5.3 Operating Timing ES237 incorporates a dual slope ADC with four phases: ZI, AZ, INT and DINT. The timing of each phase are listed below. (1) Voltage / Diode /ADP / Manual Current (for clampmeter) measurement: Phase High resolution High speed ZI 50ms 5ms AZ 25ms 2.5ms INT 100ms 10ms DINT 155ms 15.5ms (2) Current mode for multimeter/Auto Current mode for clampmeter/2-range auto voltage mode: Phase DC / AC DC Lower Range ZI 50ms 50ms AZ 25ms 25ms INT 100ms 1000ms DINT 155ms 175ms (3) Continuity / Ohm measurement: Phase Time ZI 50ms AZ 100ms INT 25ms* DINT 155ms Note: INT time = 250ms for 60.00Ω range (4) Capacitance measurement: Range Total Measurement Time 6.000nF 0.36sec 60.00nF 0.36sec 600.0nF 1.15sec 6.000μF 1.15sec 60.00μF 0.33sec 600.0μF 3.3sec (max) 6.000mF 1.32sec(max) 60.00mF 13.2sec(max) (5) Frequency / Duty cycle / VAHz measurement: Every conversion takes 1.05 second. (6) Temperature measurement: Every conversion takes 1.25 second. Note: 1. In the frequency measurement with auto mode, if the range is changed, the internal clock rate will increase ten times and the new measurement cycle becomes 1/10 times of the original cycle until the range is stable. V 2.2 34 2015/12/15 Application Circuit D 1 C3 C2 10uF C6 C7 ZR1 Bat+ DC3.0V Bat- HZ SW1 MMX HZ 7.5V 0.1uF V + ZR2 10uF Power Switch 5.6V SW8 0.1uF SW9 SW10 V- V- U1 2 Y1 4MHz 3 4 Q4 2N3904 Q6 2N3904 R15 2.2K PTC Q5 2N3904 Q7 2N3904 C10 2.2uF 5 Fin C12 5 Q10 Q9 C11 0-100pF MMX ES237 R25 REL 1 2.2K PTC SW12 Fixed 10K REL R14 200 R18 C8 R24 C22 Close toIC 2.2K PTC BKLIT R22 900 VR2 200 180K R17 BKLIT SEG27 SEG28 SEG29 BP1 BP2 BP3 BP4 ALARM ALARM1 BKOUT BZOUT SCLP SDAP CALENP 200 SLEEP R21 9K VR1 2K R23 2N3904 2N3904 SW16 RC_SW 2.2K PTC V- 1 1 200 R16 SW13 V+ 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 4 220pF C29 HOLD 3 Fixed 1K KEY SEG27 SEG28 SEG29 BP1 BP2 BP3 BP4 ALARM ALARM1 BKOUT BZOUT SCLP SDAP CALENP FREQ SLEEP OVH1 OVH OVX R1K R10K CAP CAN LPC3 LPC2 LPC1 R37 10M VR1 Bottompolygon plane Vin Gnd 470nF SW14 10K CLAMPin 1nF Metallized Polypropylene Film Capacitor : C19 Metallized Polyester Capacitor : C9, C14 , C18, C20 SW17 ACV_SW 300pF C9 KEY NC HZ MMX REL BKLIT KEY HOLD RANGE FC5 FC4 FC3 FC2 FC1 SLACDC CN CP LBAT9 VVV+ V+ DGND AGND AGND NC NC R7 C27 220pF 2.2nF C26 HOLD SW15 103 HZ 104 105 MMX 106 REL BKLIT 107 108 KEY 109 HOLD RANGE 110 111 FC5 112 FC4 FC3 113 114 FC2 FC1 115 SLACDC 116 470nF 117 118 LBAT9 119 120 121 122 123 124 125 126 127 128 D6 ACVL ACVH ADI ADO TEST5 0-100pF Q11 Q12 Size B Date: File: Title 2N3904 2N3904 RANGE D4 C16 C22 C21 C23 Precision Resistors R32 100 R33 1K R34 10.01K R35 101K R36 1.111M RANGE V- SW11 uA/mA/A SLACDC R38 99 R39 0.99 D7 VRH DACO VR_CLAMP VR_ADP 22nF 47nF 220nF 1uF OVSG SW2 uA mA FC5 uA mA D5 220nF 100nF SLACDC SW4 SW18 SW19 FC4 FC3 FC2 FC1 F? F? C19 C20 470K SW3 SW5 SW6 SW7 1 1 R40 0.01 100K mVin R8 FC5 FC4 FC3 FC2 FC1 J4 uA/mA A J5 1 2 22nF R30 C B A J6 COM 1 22nF 100nF C14 470K C15 C18 R29 Q13 Q14 R41 R27 15K 3.9K BZOUT BKOUT D1 ALARM D2 R26 1 2 3 4 D3 ALARM1 V- + C5 1uF ADO D8 1N4148 D9 1N4148 R9 R1 R2 R3 100 8 7 6 5 6 R10 V- Revision 10K JackChang V- V1 R20 47K BZ1 Buzzer Q2 2N3904 VQ3 2N3904 VQ8 2N3904 CALENP SCLP SDAP R19 47K C4 0.1uF ACVH ADI TEST5 100 100K 100 100K 100K Q1 2N3906 10K R11 BKOUT R12 HV R13 Short 4.7uF U2 VCC A0 A1 WP A2 SCL GND SDA R28 15K C30 24A02 10K C13 1uF R42 56K R43 56K 6 ACVL AVG Demo Board Circuit Number ES237 30-Oct-2014 Sheet of D:\Protel 99\Protelfile\KA035\KA035_SPEC.ddbDrawn By: D C B A 2015/12/15 35 V 2.2 IVS ADP TEMPin CLAMPin CHP CHN CIH BUFH CAZH CLN CLP CIL CAZL BUFL RAZ VRH DACO VR_CLAMP VR_ADP OHMC4 OHMC3 OHMC2 OHMC1 OVSG OR1 VR5 VR4 VR3 VR2 ACVL ACVH ADI ADO TEST5 SGND VR1 mVin LPFout 10nF C25 RS232 VBAR APOSEL VST TSEL DIS SEL1 SEL2 CESEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 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 26 27 28 29 30 31 32 33 34 35 36 37 38 C17 C24 RSOUT 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 RSOUT OSC1 OSC2 RS232 VBAR APOSEL VST TSEL DIS SEL1 SEL2 CESEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 100K 100K 100K IVS R4 ADP R5 TEMPin R6 + + + ES237 6000 Counts DMM 1. AVG Circuit 2N3904 2N3904 + SW1 Power Switch 5.6V 10uF + REL MMX HZ 7.5V 0.1uF V + ZR2 0.1uF SW8 SW9 SW10 V- V- U1 2 Y1 4MHz 3 ES237 4 SEG27 SEG28 SEG29 BP1 BP2 BP3 BP4 ALARM ALARM1 BKOUT BZOUT SCLP SDAP CALENP 200 SLEEP R14 Q4 2N3904 Q6 2N3904 C22 Close toIC R15 2.2K PTC VR2 200 R22 900 C10 2.2uF Q5 2N3904 Q7 2N3904 R21 9K VR1 2K 1 SW16 RC_SW 5 Fin Q9 Q10 R26 R27 5 Q11 Q12 Title Size B Date: File: 2N3904 2N3904 100K 4.7K Q13 Q14 1 2 3 4 5 6 7 BZOUT D1 BKOUT D2 ALARM D3 ALARM1 V- 1 2 3 4 R9 R1 R2 R3 100 6 R10 V- 10K BZ1 Buzzer Q2 2N3904 V- Q3 2N3904 V- Q8 2N3904 R20 47K V- C4 10uF C5 + VS+ 10uF VS- R19 47K CALENP SCLP SDAP VS+ VS- 22uF 8 7 6 5 100 100K 100 100K 100K Q1 2N3906 10K R11 BKOUT R12 HV R13 Short C31 4.7uF 14 13 12 11 10 9 8 C30 U2 A0 VCC A1 WP A2 SCL GND SDA 24A02 ADI U3 Buff In Buff Out NC Vin Common NC Output Offset + VS CS - VS DEN Input RMS OUT NC Cav ES5 6-Mar-2015 Sheet of D:\Protel 99\Protelfile\KA035\KA035_SPEC.ddbDrawn By: 6 JackChang TRMS ( ES5 ) Demo Board Circuit Number Revision ES237 V1 ACVH + 1 C3 C2 10uF C6 C7 ZR1 Bat+ DC3.0V Bat- HZ MMX REL C8 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 1 1 VS- VR3 500K C12 BKLIT SEG27 SEG28 SEG29 BP1 BP2 BP3 BP4 ALARM ALARM1 BKOUT BZOUT SCLP SDAP CALENP FREQ SLEEP OVH1 OVH OVX R1K R10K CAP CAN LPC3 LPC2 LPC1 Gnd Vin R37 10M VR1 Bottompolygon plane 2N3904 2N3904 VS+ C11 0-100pF SW12 10K CLAMPin 200 200 BKLIT R7 C13 220pF SW17 ACV_SW Metallized Polypropylene Film Capacitor : C19 Metallized Polyester Capacitor : C9, C14 , C18, C20 R24 R25 V- NC HZ MMX REL BKLIT KEY HOLD RANGE FC5 FC4 FC3 FC2 FC1 SLACDC CN CP LBAT9 VVV+ V+ DGND AGND AGND NC NC D6 2.2K PTC 2.2K PTC SW13 V+ 103 HZ 104 MMX 105 REL 106 BKLIT 107 KEY 108 HOLD 109 RANGE 110 FC5 111 FC4 112 FC3 113 FC2 114 FC1 115 SLACDC 116 470nF 117 118 LBAT9 119 120 121 122 123 124 125 126 127 128 SW11 uA/mA/A D4 180K KEY uA R38 99 R39 0.99 D7 Fixed 1K KEY HOLD V- uA mA mA D5 R17 R18 SW14 RANGE SLACDC FC5 FC4 FC3 SW18 SW19 R40 0.01 4 220pF C29 HOLD SW15 SW2 SW4 SW3 SW5 SW6 FC1 FC2 F? F? 3 Fixed 10K + SW7 1 1 1 1nF 470nF 0-100pF 2N3904 2N3904 RANGE SLACDC FC5 FC4 FC3 FC2 FC1 J4 uA/mA A J5 2 C26 C9 D C B A J6 COM 1 2.2nF 300pF RS232 VBAR APOSEL VST TSEL DIS SEL1 SEL2 CESEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 1 2 3 4 C17 10nF 5 6 C14 22nF 7 R29 470K 8 C15 22nF 9 C18 100nF 10 11 C19 220nF 12 C20 100nF 13 R30 470K 14 15 VRH 16 DACO 17 VR_CLAMP 18 VR_ADP 19 C16 22nF 20 C22 47nF 21 C21 220nF 22 C23 1uF 23 Precision Resistors OVSG 24 R32 100 25 R33 1K 26 R34 10.01K 27 R35 101K 28 R36 1.111M 29 30 31 ACVH 32 33 ADI 34 35 36 mVin R8 100K 37 38 R23 2.2K PTC R16 C24 C25 RSOUT 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 RSOUT OSC1 OSC2 RS232 VBAR APOSEL VST TSEL DIS SEL1 SEL2 CESEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 SEG24 SEG25 SEG26 IVS ADP TEMPin CLAMPin CHP CHN CIH BUFH CAZH CLN CLP CIL CAZL BUFL RAZ VRH DACO VR_CLAMP VR_ADP OHMC4 OHMC3 OHMC2 OHMC1 OVSG OR1 VR5 VR4 VR3 VR2 ACVL ACVH ADI ADO TEST5 SGND VR1 mVin LPFout 100K 100K 100K IVS R4 ADP R5 TEMPin R6 D C B A 2015/12/15 36 V 2.2 + ES237 6000 Counts DMM 2. Ture RMS Circuit + ES237 6000 Counts DMM Package Information 1. 128L LQFP Outline drawing 2. Dimension parameters V 2.2 37 2015/12/15