ES51981 3 1/2 AUTO DMM Features Description • 2000 count display ES51981 is an integrated analog-to-digital Converter(ADC) with 2000 counts LCD display ,automatic range selection, and 3V DC power supply. Automatic range selection is provided for voltage(AC/DC) measurement, resistor measurement and current measurement. Expensive and bulky mechanical range switches are not required. Other features include data holding, diode measurement, temperature measurement, continuity checking, low battery detection, auto- power off, re-power on, and RS232 data output. • Full automatic measurement *Voltage measurement *Current measurement *Resistor measurement • Range change function • Data hold function • Diode measurement • ADP mode with external reference voltage Application Digital Multimeter • Serial data output (RS232 format) • Auto power off (10 mins) and re-power on • Low battery detect (3V and 9V) • 3V DC power supply • Back light function 1 11/01/05 ES51981 3 1/2 AUTO DMM Pin Assignment HOLD RANGE SLACDC KEY FC5 FC4 FC3 FC2 FC1 NC C+ CNC SDO LBAT9 VVDGND AGND AGND 100 NC V+ V+ NC CL+ CLCIL CAZL BUFL IVSH IVSL OVX OVH OVSG NC OR1 VR5 VR4 VR3 VR2 TEST5 ACVL ACVH NC ADI NC ADO NC VRH VR 90 80 1 10 70 20 30 60 40 50 NC BKOUT NC XTAL NC OSC1 OSC2 NC BUZOUT BUZIN NC ANNUNC BP1 BP2 BP3 BP4 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG05 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 NC NC SEG13 SEG14 NC SEG15 BKLIT RS232 NC NC SLEEP NC NC NC NC VBAR NC VR1 SGND ADP VAVA+ 2 11/01/05 ES51981 3 1/2 AUTO DMM Pin Description Pin No 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 Symbol NC V+ V+ NC CL+ CLCIL CAZL BUFL IVSH IVSL OVX OVH OVSG NC OR1 VR5 VR4 VR3 VR2 TEST 5 ACVL ACVH NC ADI NC ADO NC VRH VR VA+ 32 VA- 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 ADP SGND VR1 NC VBAR NC NC NC NC SLEEP NC NC RS232 BKLIT SEG15 NC Type Description P P Positive supply voltage, output of on-chip DC-DC converter. Positive supply voltage, output of on-chip DC-DC converter. IO IO O O O I I I I I High resolution positive connection for reference capacitor. High resolution negative connection for reference capacitor. High resolution integrator output. Connected to integral capacitor High resolution auto-zero capacitor connection. Integral resistor connection for high resolution buffer output High current measurement input. Low current measurement input Input high voltage for resistance measurement Output connection for resistance measurement Sense low voltage for resistance measurement O O O O O I/O O O Reference resistor connection for 200.0Ω range Voltage measurement ÷10000 attenuator(2000V) Voltage measurement ÷1000 attenuator(200.0V) Voltage measurement ÷100 attenuator(20.00V) Voltage measurement ÷10 attenuator(2.000V) Test pin Negative output of AC to DC converter Positive output of AC to DC converter. I Negative input of internal AC to DC Opamp. O Output of internal AC to DC Opamp. O I I I G I Output of band-gap voltage reference .Typically –1.2V Reference input voltage connection. Typically –100mV For ADP. Deintegrating voltage positive input. The input should be higher than VA-. For ADP. Deintegrating voltage negative input. The input should be lower than VA+. ADP input Signal Ground Measurement input I Decimal point control for temperature measurement in ADP mode. O Asserts low in the sleep mode. See page 8, function description I I O Pulse low to enable serial data output. Back light function. Pulse low to set BKOUT pin output LCD segment line 15 3 11/01/05 ES51981 3 1/2 AUTO DMM …continued from previous page 49~50 SEG14~SEG1 O 3 51~52 NC 53~64 SEG12~SEG0 O 1 65 BP4 O 66 BP3 O 67 BP2 O 68 BP1 O 69 ANNUNC O 70 71 72 NC BUZIN BUZOUT 73 74 75 76 77 NC OSC2 OSC1 NC XTAL 78 79 LCD segment line 14~13 LCD segment line 12~01 LCD backplane 4 LCD backplane 3 LCD backplane 2 LCD backplane 1 Square wave output at the backplane frequency, synchronized to BP1. ANNUNC can be used to control display annunciator. Connect an LCD segment to ANNUNC to turn it on; connect an LCD segment to its backplane to turn it off. I O Enables the buzzer. Low active. Outputs an 2KHz audio frequency signal for driving piezoelectric buzzer when BUZIN is low. O I Crystal oscillator output connection Crystal oscillator input connection I NC BKOUT The chip uses internal RC oscillator if pin is connected to V-, and uses external crystal oscillator if this pin is floating or connected to DGND O 80 81 82 83 84 NC HOLD RANGE SLACDC KEY 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. I I I I 85 86 87 88 89 90 91 92 93 94 95 FC5 FC4 FC3 FC2 FC1 NC C+ CNC SDO LBAT9 I I I I I Pulse low to enable HOLD mode. Pulse low to enable manual mode and manual range selection. Select AC/DC initial state. This pin is pull low Pulse low to change mode. In ADP mode, if this pin is connected to V-, the buzzer output will be off when the ADP input overflows. Switch 5 for function selection. Switch 4 for function selection. Switch 3 for function selection. Switch 2 for function selection. Switch 1 for function selection. O O Positive capacitor connection for on-chip DC-DC converter. Negative capacitor connection for on-chip DC-DC converter. O I 96 97 98 99 100 VVDGND AGND AGND RS232 compliant serial data output. Low battery configuration. If 3V battery is used, connect it to AGND. The default low-battery threshold voltage is –2.3V. If 9V battery is used, the low battery annunciator is displayed when the voltage of this pin is less than VRH (-1.2V) Negative supply voltage. Connecting to battery negative terminal. Negative supply voltage. Connecting to battery negative terminal. Digital ground, connected to battery positive terminal. Analog ground. Analog ground. P P G G G 4 11/01/05 ES51981 3 1/2 AUTO DMM 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 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℃ Electrical Characteristics TA=25℃, V- = -3V Parameter Power supply Operating supply current In DCV mode Voltage roll-over error Voltage nonlinearity Input Leakage Low battery flag voltage Zero input reading Reference voltage and open circuit Voltage for 200Ω measurement Symbol Test Condition VIDD Normal operation ISS In sleep mode REV 10MΩ input resistor Best case straight NLV line VREF Peak to peak backplane Drive voltage Counter time base period Open circuit voltage for Ω Measurement (except 200Ω) Internal pull-high to 0V Current Internal pull-low to VCurrent AC frequency response at 2.000V range Reference voltage temperature Coefficient TCRF V- to AGND 10MΩ input resistor 100KΩ resistor between VRH and AGND -3.5V≤ V ≤-2.2V fOSC = 4MHZ Ω and Continuity Mode Between V- pin and HOLD, RANGE, KEY, FC1, FC2, FC3, FC4, FC5, XTAL, BKLIT Between V- pin and RS232 Between GND Pin and SLACDC ±1% ±5% 100KΩ resister Between VRH 0℃<TA<70℃ 5 Min. -3.5 — — — Typ. -3.0 0.9 0.1 — Max -2.2 1.1 5 ±0.1 Units V mA µA %F.S — — ±0.1 %F.S -10 -2.5 -000 1 -2.3 000 10 -2.1 +000 PA V counts -1.3 -1.2 -1.1 V 3.00 3.2 3.40 V — 1 — sec -0.54 -0.47 -0.4 V — 1.2 — — 11 — 1.5 µA µA — — 40-400 400-2000 — — HZ — 50 — ppm/℃ 11/01/05 ES51981 3 1/2 AUTO DMM Note: 1.Full Scale Function Description 1. Operating Modes 1.1 Voltage Measurement A reconfigurable 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 VR3 VR5 Full Scale Range 200.0mV 2.000V 20.00V 200.0V 2000V Divider Ratio 1 1/10 1/100 1/1000 1/10000 Resister Connection R2 / (R1+R2) R3 / (R1+R3) R4 / (R1+R4) R5 / (R1+R5) 1. 200.0mV range only exists in manual mode. 2. In the 2000V range, if the digit numbers is larger than 1000V, LCD will display “OL”. The measurement of true RMS using ES636 If ES636 (or other true RMS-to-DC converter chip) is used for true RMS measurement, the suggested application circuit is shown below. When ES636 is used for true RMS, ADO and ADI pin short together, TEST5 pin keeps floating, and ACVL pin connects to SGND. And the OVSG pin shorts to AGND through a switch. 6 11/01/05 ES51981 3 1/2 AUTO DMM 2.2u + -Vs 14 13 12 11 10 150 9 8 ES636 4.7u 1 2 3 4 5 6 7 100 1K 10K 101K 1.111M +Vs OVSG OR1 VR5 VR4 VR3 VR2 ES51981 ACV TEST5 ACVL ACVH 10K +Vs 500K 2.2u + -Vs ADI ADO AGND 1k 22k 1.2 Resistance Measurement A reconfigurable 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 200.0Ω 2.000KΩ 20.00KΩ 200.0KΩ 2.000MΩ 20.00MΩ Divider Ratio R6 R5 R4 R1‖R3 R1‖R2 R1 Resister Connection 100Ω 1KΩ 10KΩ 100KΩ 1MΩ 10MΩ 1.3 Current measurement Current measurement has three modes. The following table summarizes the full scale range of each mode. Mode Automatic Mode 1 Automatic Mode 2 Automatic Mode 3 Manual Mode Range Selection µA mA A A 7 Full Scale 200.0µA / 2000µA 20.00mA / 200.0mA 20.00A/2.000A 20.00A 11/01/05 ES51981 3 1/2 AUTO DMM 1.4 Continuity Check Continuity check shares the same configuration with 200.0Ω manual resistance measurement mode, but with buzzer output to indicate continuity. The buzzer generates a 2KHz sound whenever the digit number less than 25Ω. Because the cycle time of measurement is only 50ms, the least significant digit will not display. 1.5 Diode Measurement Diode measurement mode shares the same configuration with 2.000V manual voltage measurement mode. 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”. The buzzer generates a 2KHz sound whenever the digit number is less than 0.25V. Because the cycle time of measurement is only 50ms, the least significant digit will not display. 8 11/01/05 ES51981 3 1/2 AUTO DMM 1.6 Auto power off ES51981 has a default auto power off function. If the meter idles for more than 10 minutes, the chip automatically turns the power off. When this happens, the state of the meter is saved. In order to disable auto power off function, power on the meter when any of the push function, except for HOLD, is pressed down. In addition, when RS232 output is active, the auto power-off function is also disabled. The APO sign on the LCD panel indicates whether the auto power-off is enabled or not. Note: Powering on the meter while pressing HOLD turns on all LCD segment until HOLD is pressed again. 1.7 Sleep The meter enters sleep mode after auto power off. The SLEEP pin asserts low (-3V) in the sleep mode, and asserts high (+3V, not 0V) after re-power on. 1.8 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. 2. Measurement Mode Switching Measurement mode depends on the logic level of FC1, FC2, FC3, FC4, FC5, and KEY. When FC5 is HIGH, the measurement modes are listed in the following table. SLACDC 0 0 0 0 0 1 1 1 1 1 X X X X X FC1 1 1 1 1 0 1 1 1 1 0 0 0 0 0 0 FC2 0 1 1 0 0 0 1 1 0 0 0 1 0 1 1 FC3 1 0 1 0 0 1 0 1 0 0 1 0 0 1 0 FC4 1 1 1 1 0 1 1 1 1 0 1 1 1 1 0 Mode Function of KEY Voltage Measurement DCV(initial) ↔ACV Current Measurement(µA) DCA(initial) ↔ACA Current Measurement(mA) DCA(initial) ↔ ACA Manual Current Measurement(A) DCA (initial) ↔ACA Auto Current Measurement(A) DCA(initial) Voltage Measurement ACV (initial) ↔DCV Current Measurement(µA) ACA(initial) ↔DCA Current Measurement(mA) ACA (initial) ↔DCA Manual Current Measurement(A) ACA (initial) ↔DCA Auto Current Measurement(A) ACA (initial) Resistance Measurement Ω ↔ Continuity Resistance Measurement Ω ↔ Diode Continuity Check Continuity Diode Resistance Measurement Ω ↔ Continuity ↔Diode — Temperature(℃) Ps. X means “don’t care” 9 11/01/05 ES51981 3 1/2 AUTO DMM When FC5 is LOW, KEY is disable. The corresponding measurement modes are list below SLACDC 0 0 0 0 0 1 1 1 1 1 X X X X X FC1 1 1 1 1 0 1 1 1 1 0 0 0 0 0 0 FC2 0 1 1 0 0 0 1 1 0 0 0 1 0 1 1 FC3 1 0 1 0 0 1 0 1 0 0 1 0 0 1 0 FC4 Mode 1 AC Voltage Measurement 1 AC Current Measurement(µA) 1 AC Current Measurement(mA) 1 Manual AC Current Measurement(A) 0 Auto AC Current Measurement(A) 1 DC Voltage Measurement 1 DC Current Measurement(µA) 1 DC Current Measurement(mA) 1 Manual DC Current Measurement(A) 0 Auto DC Current Measurement(A) 1 Resistance Measurement 1 Resistance Measurement 1 Continuity Check 1 diode Measurement 0 Temperature(℉) Ps. X means “don’t care” The other combinations of FC1, FC2, FC3, and FC4 are for ADP modes. In ADP modes , if FC5 is LOW, the minus sign on the LCD panel will not be displayed. And if KEY pin is floating, the buzzer beeps when the input signal is overflow. The ADP mode function is summarized below. FC1 1 1 1 1 FC2 1 1 0 0 FC3 1 0 0 1 FC4 0 0 0 0 Mode ADP0 ADP1 ADP2 ADP3 Note: Temperature measurement mode takes input signal from ADP pin. In temperature measurement mode, VBAR pin is used to control the right most digit point on the LCD panel. When VBAR is LOW, this digit point is displayed. 3. Push function 3.1 HOLD 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. HOLD function can be cancelled by changing the measurement mode, pressing RANGE, or push HOLD again. 10 11/01/05 ES51981 3 1/2 AUTO DMM 3.2 Range 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 Measurement Mode Auto Manual V(DC/AC) VR2 – VR5 VRi → VRi + 1, VR5 → VR1 µA(DC/AC) R1 – R2 R1 → R2, R2 → R1 mA R1－R2 R1 → R2 (AC/DC) R2 → R1 Auto A(DC/AC) R1 – R2 R1 → R2, R2 → R1 A(DC/AC) fixed fixed ORi → Ω OR1- OR6 ORi + 1, OR6 → OR1 Continuity fixed fixed Diode Fixed fixed Control Range Initial Range 200.0mV – 2000V 2.000V 200.0µA - 2000µA 200.0µA 20.00mA – 200.0mA 20.00mA 2.000A – 20.00A 2.000A 20.00A 20.00A 200.0Ω – 20.00MΩ 200.0Ω 200.0Ω 2.000V 200.0Ω 2.000V Note: Pushing RANGE resets all existing special modes. 3.3 KEY See Section “Measurement Mode Switching” for the function of this pin. 4. Serial Data Output The serial data sent to SDO pin twice every A/D conversion cycle. The data format complies with JIS 7Bits transmission code with a baud rate of 19230. The host can use RS232 interface to read the data. A single data packet includes a start bit (always 0), 7 data bits, an odd 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. The LSB is sent first and the MSB is sent last. 11 11/01/05 ES51981 3 1/2 AUTO DMM single package 0V -3V 0 D0 ~D6 LSB p 1 P MSB One data block consists of 11 packets, or 110 bits. The following figure shows the format of a data block. The range packet indicates the full scale range of the meter. Digit 3 through digit 0 are just the digits on the LCD panel. The function packet indicates the measurement mode of the meter. Status, option 1 and option 2 give the status of the meter. CR and LF are delimiters used to separate the blocks. All package p 1 0 0 range p 1 0 digit3 p 1 0 0 digit1 digit0 p 1 0 p 1 0 CR p 1 function p 1 option2 option1 status 0 digit2 p 1 0 p 1 0 0 p 1 p 1 LF The meter always outputs the current input value to the serial port in spite of HOLD mode. Each block is repeated twice in one conversion cycle. The detailed data format of each packet is listed below. 12 11/01/05 ES51981 3 1/2 AUTO DMM 4.1 FUNCTUON This packet indicates the measurement mode of the meter. The following table summarizes the transmitted code for each mode. Note that the encoding of this packet is different from the encoding of FC1-FC4 switch. Code 0111011 0111101 0111111 0110000 0111001 0110011 0110101 0110001 0110100 0111110 0111100 0111000 0111010 Measurement Mode Voltage µA Current mA Current Auto A current Manual A Current Ω Continuity Diode 1*Temperature ADP0 ADP1 ADP2 ADP3 Note: 1*.The judge bit in the Status packet determines whether the unit is Celcius or Fahrenheit. 4.2 RANGE This packet indicates the full scale range of the meter. When the meter operates in continuity mode, diode mode, or current (A) mode, this packet is always 0110000 since the full scale range in these modes are fixed. The following table lists the code for each range in each measurement mode. Code 0110000 0110001 0110010 0110011 0110100 0110101 0110110 V 2.000V 20.00V 200.0V 2000V 200.0mV mA 20.00mA 200.0mA µA 200.0µA 2000µA Auto A 2.000 A 20.00 A Ω 200.0Ω 2.000KΩ 20.00KΩ 200.0KΩ 2.000MΩ 20.00MΩ 4.3 DIGIT 3 – DIGIT 0 Digit 3 is the most significant digit on the LCD panel, and digit 0 is the least significant digit. When the LCD panel shows OL, the serial port outputs 2000. 13 11/01/05 ES51981 3 1/2 AUTO DMM Digit 0 1 2 3 4 5 6 7 8 9 Code 0110000 0110001 0110010 0110011 0110100 0110101 0110110 0110111 0111000 0111001 Because the cycle time of measurement for continuity/diode mode is only 50ms, the least significant digit may not be accurate. 4.4 STATUS The format of this shown below. The Judge field is meaningful only when the Function packet indicates Temperature mode. In Temperature mode, judge is 1 if the unit is ℃ and is 0 of the unit is ℉ . Sign field indicates whether the minus sign on the LCD panel is on or off. BATT field is one of battery low condition is true. OL indicates input overflow. 0 BIT 6 1 BIT 5 1 BIT 4 Judge BIT 3 Sign BIT 2 BATT BIT1 OL BIT 0 1 BIT 4 HOLD BIT 3 0 BIT 2 0 BIT1 0 BIT 0 4.5 OPTION 1 This packet is not used. 0 BIT 6 1 BIT 5 If Hold field is 1, Hold function is active. Hold function will not influence Digital 3~0 which is related to current measured value. 4.6 OPTION 2 This packet contains information on the operation mode of the meter. The format is shown below. The DC field indicates that the meter operates in DC measurement mode, either voltage or current. The AC field indicates that the meter operates in AC measurement mode, either voltage or current. The AUTO field is set to one if the meter operates in automatic mode, and is set to zero when the meter operates in manual mode. 0 BIT 6 1 BIT 5 1 BIT 4 DC BIT 3 14 AC BIT 2 AUTO BIT1 0 BIT 0 11/01/05 ES51981 3 1/2 AUTO DMM 4.7 CR Carrage return. The transmitted code is 0001101. 4.8 LF Line feed. The transmitted code is 0001010. 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 junctions 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 25Ω(0.25V) (6) Auto power off generates a 2KHz beep which lasts for 1.5 seconds. The following figures shows 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 15 11/01/05 ES51981 3 1/2 AUTO DMM 5.1 LCD Panel 1 BATT AUTO MANU DC AC HOLD ℃ ℉ µ2 m2 V A APO MKΩ RS232 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 BP1 BATT DC AUTO MANU A3 B3 HOLD A2 BP2 AC F4 A4 B4 F3 G3 F2 B2 BP3 APO — G4 C4 E3 C3 E2 G2 BP4 RS232 E4 D4 P3 D3 P2 D2 C2 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 BP1 V A m2 u2 ℃ BP2 F1 A1 B1 M × × ℉ BP3 E1 G1 C1 × × × × BP4 P1 D1 K Ω × × × 16 11/01/05 ES51981 3 1/2 AUTO DMM 5.2 LCD Backplane Waveform V- +3.1 VV- +3.1 VV- +3.1 VV- +3.1 VV- +3.1 V- 5.3 LCD display on condition LCD Annunciator V Condition In voltage measurement mode, and diode measurement mode. A In current measurement mode. Ω In resistance measurement mode, and continuity mode. In continuity check mode. In diode mode. 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. m2 In voltage or current measurement mode and the full scale range is in the order of 10-3. u2 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 ℉ APO - When auto power off function is enabled. In voltage or current measurement mode and when the input is negative. 17 11/01/05 ES51981 3 1/2 AUTO DMM 5.4 Operating Timing ES51981 incorporates a dual slope ADC with four phases: ZI, AZ, INT and DINT. The timing of each phase is listed below. *Voltage /ohm/ADP measurement: Phase ZI AZ INT DINT Time 100ms 100ms 100ms 200ms Ps. In the voltage and ohm 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. *Current mode Phase ZI AZ INT DINT Time 100ms 100ms 100ms 100ms *Continuity/diode measurement Phase ZI AZ INT DINT Time 10ms 10ms 10ms 20ms 18 11/01/05 ES51981 3 1/2 AUTO DMM 6.Test circuit 1. Voltage test 4.Current test AGND OVSG 100 1K 10K 101K 1.11M D2 D1 1.0u 0.47u 1.0u OR1 VR5 VR4 VR3 VR2 ADO 88M ADI ACVL ACVH TEST5 0.1u 15K 10K 15K 5K 0.005 20A 0.045 0.45 2A mA 4.5 A V R 1 V R mA 45 mA uA AGND SGND 100K uA uA IVSH 100K IVSL 450 10M -100mV Voltage input 5.ADP test 2.Resistor test VA+ OVX Z1 6V Z2 100 100 1K 10K 101K 1.11M 100K ADPin- OVH OVSG VAADP -100mV ADPin+ PTC 1.5K SGND AGND OR1 VR5 VR4 VR3 VR2 SGND AGND 3.Diode test 6. Low battery AGND Z1 6V Z2 100 9V OVH BA PTC 1.5K 10M 1.11M 680K TT VR1 270K LBAT9 0.1u AGND V- 0V VR2 OVSG 19 11/01/05 ES51981 3 1/2 AUTO DMM 7.Application circuit 7.5V 5.6V ZI 0.1u + 450 uA uA mA 10u + 0.1u -3V 0.1u HOLD RANGE SLACDC KEY FC5 FC4 FC3 FC2 FC1 NC C+ CNC SDO LBAT9 VVDGND AGND AGND uA 4.7u 3V 10M 100K -3V -3V Note: In order to prevent IC from damaging by inappropriate operation, the Zener diodes MUST be required as protection. 20 11/01/05 -3V Display 20K (50)SEG13 SEG14 NC SEG15 BKLIT RS232 NC NC SLEEP NC+ (40)NCNC NC VBAR NC VR1 SGND ADP VAVA+ + 4MHz LCD NC BKOUT NC XTAL NC OSC1 OSC2 NC BUZOUT BUZIN NC ANNUNC BP1 BP2 BP3 BP4 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 NC NC NC V+ V+ 4.5 mA NC mA CL+ 0.1u CLA 0.45 2A 0.22u CIL 0.1u 0.045 20A 100K CAZL BUFL 0.005 IVSH(10) 100K IVSL SGND 100K 110pF 100 OVX 100K OVH 1.5K OVSG R PTC NC 100 OR1 1K Zener 6V VR5 10K 101K VR4 VR3 1.11M VR2(20) 10K TEST5 ACVL 5K ACVH NC 15K 15K 0.1u ADI 1u 1u NC 88M D1 D2 0.47u ADO NC 91K VRH 1u VR(30) 45 ES51981 3 1/2 AUTO DMM Package 1 100 Pin QFP Package 2 Dimension Paramenters 21 11/01/05