ES51927

ES51927 6000 Counts Smart DMM Features 6000 counts LCD display 3V DC power supply Conversion rate: 3 times/s (voltage mode) Full automatic measurement: *Voltage/Current: AC/DC auto scanning & auto range: 6.000V~1000V *Resistance/Diode/Capacitance(RDC scan) Auto scanning & auto range: Resistance: 600.0Ω~6.000MΩ Capacitance: 6.000nF~600.0uF Push functions Function selection by single key Range change function Hold function VAHZ function Back light function Support non-contact voltage detection High voltage (> 30V) indication of LCD display for voltage measurement Built-in HCF(high crest factor detection) function in AC mode OL level selection (600V/1000V/1500V) Band-gap reference voltage output Auto power off (3min. or 10min.) & repower on Sleep output indication On-chip buzzer driver Low battery detection ES51927 is an integrated ADC with 6000 counts LCD display driver. It could support fully automatic DMM function measurement. In voltage or current mode, the AC or DC signals auto scanning. In R/D/C (passive component) mode, resistance (including continuity), capacitance or diode measurements are allowed by fully automatic detection. A single key and simple switch could select all measurements. Expensive and bulky mechanical range switches are not required. A non-contact electric field detector (EF mode) is built-in for ac voltage measurement also. Other features including range control, data hold, VAHz and back light function are available. For power saving, an auto power off & re-power on scheme are built-in. A sleep output is the indication of entering auto power off mode. General description Application Smart digital multi-meter Smart clamp meter Ver 2.7 1 07/10/03 ES51927 6000 Counts Smart DMM Pin Assignment 70 65 60 55 SEG12 SEG13 SEG14 SEG15 CLAMP VON AON FA FUA FC3 FC2 FC1 HOLD SEL VAHZ RANGE NC BKLIT EFEN BP1 BP2 BP3 BP4 ANNUNC BKOUT 75 50 10 15 20 Pin Description Pin No 1 2 Symbol AGND LBAT 3 4 5 6 7 8 9 Ver 2.7 CREF+ CREFCINT CAZ BUFF RAZ IVSH AGND LBAT CREF+ CREFCINT CAZ BUFF RAZ IVSH IVSL OVX OVH OVSG OR1 VR5 VR4 VR3 VR2 TEST5 ACVL ACVH ADI ADO OHMC4 OHMC3 Type 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. 2 07/10/03 I/O I/O O I O O I 25 5 SEG11 SEG10 NC NC SEG09 SEG08 SEG07 SEG06 SEG05 SEG04 SEG03 SEG02 SEG01 OSC2 OSC1 BKSEL CESEL C+ CVVV+ V+ DGND AGND 80 45 85 Cyrustek. com.tw 40 90 ES51927 35 95 30 100 NC NC NC NC NC ACEN BUZOUT APOSEL BUZIN SLEEP R1K R9KCA+ CANC VR1 VAVA+ ADP SGND VR VRH NC OHMC1 OHMC2 ES51927 6000 Counts Smart DMM 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 39 40 41 42 43 44 45 46 – 50 51 52 IVSL OVX OVH OVSG OR1 VR5 VR4 VR3 VR2 TEST5 ACVL ACVH ADI ADO OHMC4 OHMC3 OHMC2 OHMC1 NC VRH VR SGND ADP VA+ VAVR1 NC CACA+ R9K R1K SLEEP BUZIN APOSEL BUZOUT ACEN NC BKOUT ANNUNC I I I I O O O O O I/O I I I O O O O O O I I I I I I I/O I/O O O O I I O O O O Low current measurement input Input high voltage for resistance/capacitor measurement Output connection for resistance/capacitor measurement Sense low voltage for resistance measurement Reference resistor connection for 600.0Ω range Voltage measurement ÷10000 attenuated (1000V) Voltage measurement ÷1000 attenuated (600.0V) Voltage measurement ÷100 attenuated (60.00V) Voltage measurement ÷10 attenuated (6.000V) 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 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 be lower than VA+. Measurement input. 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. 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 manual mode and manual range selection. 3 07/10/03 53 54 55 56 57 58 59 60 Ver 2.7 BP4 BP3 BP2 BP1 EFEN BKLIT NC RANGE O O O O I I I ES51927 6000 Counts Smart DMM 61 62 63 64 65 66 67 68 69 70 71 72 – 77 78 – 79 80 – 88 89 90 91 92 93 94 95 96 97 98 99 100 VAHz SEL HOLD FC1 FC2 FC3 FUA FA AON VON CLAMP SEG15 – 10 NC SEG09 - 01 OSC2 OSC1 BKSEL CESEL C+ CVVV+ V+ DGND AGND I I I I I I I I I I I O O I O 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 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 I BKOUT will be active. If BKLIT is back to high level, the BKOUT would be inactive. I OL selection feature control pin. O Positive capacitor connection for on-chip DC-DC converter. O Negative capacitor connection for on-chip DC-DC converter. P Negative supply voltage. Connecting to battery negative terminal. P Negative supply voltage. Connecting to battery negative terminal. P/O Output of on-chip DC-DC converter. P/O Output of on-chip DC-DC converter. G Digital ground. G 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 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℃ Ver 2.7 4 07/10/03 ES51927 6000 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 600Ω measurement Open circuit voltage for Ω measurement (except 600Ω) Symbol Test Condition VIDD Normal operation ISS In sleep mode REV 10MΩ input resistor Best case straight NLV line V- to AGND 10MΩ input resistor -3.5V≤ V ≤-2.2V 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 ±1% ±5% VR1(10MΩ input impedance) ADP, IVSL and IVSH Parasitic capacitance allowed in 6.000MΩ range Forward voltage Min. -3.5 — — — — -10 -2.4 -000 3.0 — -1.33 -0.86 Typ. -3.0 2.5 0.6 — — 1 -2.3 000 3.15 1 -1.23 -0.78 Max -2.5 — 2.5 ±0.1 ±0.1 10 -2.2 +000 3.3 — -1.13 -0.70 Units V mA µA %F.S1 %F.S PA V counts V sec V V VREF 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 — 1.2 — µA — — 10 300 8 — 40-400 — 400-2000 — — 50000 400 10 — 0.8 — 50 — — — — 500 12 200 HZ Hz mV mV pF V pF ppm/℃ %F.S counts %F.S counts RDC scan mode DIODE sensitivity RDC scan mode CAP sensitivity Reference voltage temperature 100KΩ resister coefficient TCRF Between VRH 0℃ 2s enter power down mode R/D/C auto scan Resistance measurement Continuity measurement Push SEL key < 1s Diode measurement Capacitance measurement Note: * Available when EF_EN is active only Ver 2.7 13 07/10/03 ES51927 6000 Counts Smart DMM 3.2 Range function RANGE pin switches to and from automatic and manual mode, and while in manual mode, changes the full-scale range. The following figure shows the state transition. 1 push < 1 sec Automatic Mode 1 push > 1 sec Manual Mode Range up 1 push < 1 sec 3.3 Hold and delay-hold function The data hold mode makes the meter stop updating the LCD panel. This mode can be nested in most of the special modes. In auto scanning mode, the HOLD key is not available. Enabling hold function in automatic mode makes the meter switch to manual mode. Hold function can be cancelled by changing the measurement mode, pressing RANGE, or push HOLD again. The delay-hold function is enabled when HOLD key is pressed larger than 2 seconds. When delay-hold function is entered successfully, the meter will stop to update the LCD data after six seconds delayed. During the six seconds waiting, the HOLD symbol on LCD panel will be blinking. Push > 2s 6sec past Normal mode Push < 2s HOLD mode (Auto/Manual) Push < 2s (Manual) Push > 2s Push < 2s Delay State (Auto/Manual) Ver 2.7 14 07/10/03 ES51927 6000 Counts Smart DMM 3.4 VAHz function When voltage or current measurement mode is selected, the VAHz funtion is available. Push VAHz key to select this frequency measurement mode. The frequency is measured by auto ranging. The maximum frequency range is 100kHz. The sensitivity of signal input is 10% full scale of voltage or current mode typically. Configuration FR1 FR2 FR3 Range 6.000KHz 60.00KHz 100.0KHz 3.5 Back light function When BKSEL is set to DGND or floating, push the BKLIT key to enable the back light output driving ON/OFF. If the auto back light configuration is active, the BKLIT becomes a control input for external light sensed circuit. Set to low for one second to active the back light output driving. Set to high then the driving output is inactive immediately. BKSEL DGND or floating VConfiguration Normal back light function Auto back light function Ver 2.7 15 07/10/03 ES51927 6000 Counts Smart DMM 4. Miscellaneous The conditions, which the meter turns on the buzzer, include: (1) Changing measurement mode generates one beep. (2) Pressing any of the push functions generates one beep, if the function is valid. (3) Power on and re-power on generate one beep. (4) Input overflow in voltage and current mode generates one beep every 0.3 seconds (or 3.33 beeps per second.) (5) Continuity (diode) check generates a continuous 2KHz beep whenever the measurement is less then 30Ω(30mV) (6) Auto power off or power down by SEL key generates a 2KHz beeper that lasts for 1.5 seconds. The following figures show the output waveform from the BUZOUT pin. 0.5 mS (a) Continuous 2KHz beep 0.15 sec 0.3 sec (b) 3.33 beep/sec Ver 2.7 16 07/10/03 ES51927 6000 Counts Smart DMM 4.1 LCD configuration S14 S12 S7 S8 S9 S10 S11 S15 APO S1 S2 S3 S4 S5 S6 S13 BP1 BP2 SCAN AUTO MANU AC HOLD µ2 m2 V A n µ1 m1 F M K Ω Hz BP3 DC BP4 BATT SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 BP1 SCAN AUTO BP2 AC BP3 DC BP4 BATT DP3 BP1 BP2 BP3 BP4 A1 F1 E1 D1 B1 G1 C1 A4 F4 E4 D4 µ2 m2 V A MANU B4 G4 C4 M K Ω A3 F3 E3 D3 n µ1 m1 F Hz HOLD B3 G3 C3 F2 E2 DP2 APO A2 G2 D2 B2 C2 DP1 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 Ver 2.7 17 07/10/03 ES51927 6000 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 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. 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. HOLD m1 n m2 M K APO µ1 µ2 Ver 2.7 18 07/10/03 ES51927 6000 Counts Smart DMM Test Circuit 1. Voltage test AGND OVSG 100 1K 10K 101K 1.111M D1 1.0u 15K 1.0u 10K 10K +4.7u D2 15K OR1 VR5 VR4 VR3 VR2 ADO ADI ACVL ACVH TEST5 A mA uA V R 1 10M -400mV Voltage input Z1 6V Z2 100 PTC 1.5K 10M 1.111M VR1 V R 450 0.005 0.495 mA 4.5 50 mA uA uA 100K 100K IVSH IVSL 60A 4. Current test AGND SGND 5. Diode test AGND OVH 2. Resistance test 22n 220n PTC 1.5K Z1 6V Z2 470n 47n 100 100 1K 10K 101K 1.111M OVX OHMC4 OHMC3 OHMC2 OHMC1 OVH OVSG OR1 VR5 VR4 VR3 VR2 SGND AGND VR2 OVSG 6. Low battery 9V BA TT 270K 0V 680K LBAT9 0.1u AGND V- 3. Current test for clampmeter 7. EF test EFin+ RL VR R 100K ADP SGND AGND 400mV 100k 120M ADP SGND AGND VA+ VA- EFin- Ver 2.7 19 07/10/03 ES51927 6000 Counts Smart DMM Application Circuit a.) AC average rectified circuit 1 2 3 4 5 6 V- uA D SW1 SW SPDT BT1 SW2 uA ZR3 C3 ZR1 R1 ZR2 C4 SW3 uA C1 10uF C2 0.1uF SW4 R3 mA U1 3V 5.6V 10uF 0.1uF ZR4 mA Y1 450 C5 + 0.47uF 4MHz + LCD Panel J1 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 BP1 BP2 BP3 BP4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CON19 D CESEL BKSEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 R2 45 4.5 SW5 R4 60A 1 J2 R5 Gnd 1 J4 mA C7 C C8 R7 R8 IVSH R9 R10 IVSL 100K C6 220pF R17 ZR7 1 J3 1.5K PTC ZR8 R12 R13 R14 R15 R18 100 1K 10K 101K 1.11M TEST5 ACVL ACVH ADI ADO 220nF 220nF 470K 150K 100K 100K R11 VR1 100 C9 0.1uF LBAT AGND DGND V+ V+ VVCC+ CESEL BKSEL OSC1 OSC2 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 NC NC SEG10 SEG11 ZR5 ZR6 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 C13 220nF C14 C15 470nF 47nF 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 SEG10 SEG11 0.495 SW6 60A R6 0.005 R/C/D/Cont SW7 SW SPST 20K IN VR1_10M OHMC2 OHMC1 NC VRH VR SGND ADP VA+ VAVR1 NC CACA+ R9K R1K SLEEP BUZIN APOSEL BUZOUT ACEN NC NC NC NC NC AGND LBAT CREF+ CREFCINT CAZ BUFF RAZ IVSH IVSL OVX OVH OVSG OR1 VR5 VR4 VR3 VR2 TEST5 ACVL ACVH ADI ADO OHMC4 OHMC3 + 7.5V + ES51927 SEG12 SEG13 SEG14 SEG15 CLAMP VON AON FA FUA FC3 FC2 FC1 HOLD SEL VAHz RANGE NC 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 SEG12 SEG13 SEG14 SEG15 CLAMP VON AON FA FUA FC3 FC2 FC1 HOLD SEL VAHZ RANGE BKLIT EFEN BP1 BP2 BP3 BP4 ANNUNC C Function Switch VBKLIT RANGE VAHZ SEL HOLD SW8 SW_non lock SW9 SW_non lock SW10 SW_non lock SW11 SW_non lock SW12 SW_non lock FC3 FC2 FC1 EFEN FA FUA AON VON CLAMP SW13 SW_lock SW14 SW_lock SW15 SW_lock SW16 SW_lock SW17 SW_lock SW18 SW_lock SW19 SW_lock SW20 SW_lock SW21 SW_lock V- C11 B 22nF B VR2 10K R16 10K C10 TEST5 4.7uF ADI C12 R23 1uF + R19 VR1_10M R20 C16 100K + R21 15K + C17 R24 D1 1N4148 D2 IN4148 ACVH ADO ACVL 1 J5 C19 220nF A 1 Notes: 1. The ESD protection circuits protect most of pins. However pins, V+, V-, AGND, DGND and VR1 are not protected enough because the parasitic effect must be decrease. Therefore enough external protection is needed for assembling, carrying and keeping. In addition, components connecting to these unprotected pins have to be soldered on board before the IC is soldered. 2. All the zener diodes above are used for IC protection. These protections are needed and these zener diodes must be soldered on PCB first before soldering ES51927 on. 3. The OVX pin resistance have to be kept below 120kΩ for the capacitance mode accuracy (6/60nF range). For higher voltage protection, additional configuration of PTC protection is necessary. Ver 2.7 + 1uF C18 1uF R22 15K 27K VR3 VR ADP 26 27 28 56K 29 30 31 32 VA+ 33 34 VA10M 35 36 37 470nF 38 39 40 41 42 43 44 45 46 47 48 49 50 APOSEL BUZIN SLEEP R26 9K VZR9 R25 1K 5.6V 10K BZ1 Buzzer Title Size B Date: File: Average Circuit A ES51927 6000 Counts Smart DMM Number Application Circuit ( Average ) Sheet of Drawn By: 6 Revision 30-Aug-2007 D:\Protel file\ES51928 Serial.ddb 2 3 4 5 20 07/10/03 ES51927 6000 Counts Smart DMM b.) AC RMS circuit 1 2 3 4 V5 6 uA BT1 SW2 uA ZR3 C3 ZR1 R1 ZR2 C4 SW3 uA C1 10uF C2 0.1uF SW4 R3 mA U1 3V 5.6V 10uF 0.1uF ZR4 SW SPDT J1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 CON19 D SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 BP1 BP2 BP3 BP4 mA Y1 450 C5 + 0.47uF 4MHz LCD Panel SW1 + D CESEL BKSEL SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 R2 45 4.5 SW8 R4 60A 1 J2 VGnd R5 mA C7 C8 R8 R9 IVSH R10 IVSL R11 100K C6 220pF R7 ZR7 1.5K PTC ZR8 R13 R14 R15 R16 R17 100 1K 10K 101K 1.11M ACVL ACVH ADO 1 220nF 220nF 470K 150K 100K 100K R12 VR1 100 C9 0.1uF LBAT AGND DGND V+ V+ VVCC+ CESEL BKSEL OSC1 OSC2 SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09 NC NC SEG10 SEG11 ZR5 ZR6 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 C12 220nF C13 470nF 47nF 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 SEG10 SEG11 0.495 SW9 60A R6 Function Switch C 0.005 1 J3 BKLIT RANGE VAHZ SEL HOLD SW5 SW_non lock SW6 SW_non lock SW7 SW_non lock SW11 SW_non lock SW12 SW_non lock R/C/D/Cont SW10 SW SPST 20K J4 ACV / RMS SW_lock C10 22nF B VCLAMP VON AON FA FUA FC3 FC2 FC1 EFEN SW13 SW_lock SW14 SW_lock SW15 SW_lock SW17 SW_lock SW18 SW_lock SW19 SW_lock SW20 -VS_ES7 +VS_ES7 C16 C17 + 10uF VR3 50K ES7PWR -VS_ES7 1 2 3 4 R23 47K 26 27 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 OHMC2 OHMC1 NC VRH VR SGND ADP VA+ VAVR1 NC CACA+ R9K R1K SLEEP BUZIN APOSEL BUZOUT ACEN NC NC NC NC NC IN SW16 AGND LBAT CREF+ CREFCINT CAZ BUFF RAZ IVSH IVSL OVX OVH OVSG OR1 VR5 VR4 VR3 VR2 TEST5 ACVL ACVH ADI ADO OHMC4 OHMC3 + 7.5V + ES51927 SEG12 SEG13 SEG14 SEG15 CLAMP VON AON FA FUA FC3 FC2 FC1 HOLD SEL VAHz RANGE NC 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 SEG12 SEG13 SEG14 SEG15 CLAMP VON AON FA FUA FC3 FC2 FC1 HOLD SEL VAHZ RANGE BKLIT EFEN BP1 BP2 BP3 BP4 ANNUNC C VR1_10M C14 B ES7PWR R20 100K TRMS Circuit R18 5K R19 -VS_ES7 +VS_ES7 VR1_10M R21 C15 APOSEL BUZIN SLEEP R22 9K C11 1uF + 27K VR2 VR ADP 10K R26 + 5 U3 TL061 -VS_ES7 R25 VR4 100K 1.5K 220nF RL COM Vin + VS PwrDown Vout - VS Cav U2 C18 ES7 2.2uF 8 7 6 5 2 3 1 6 ACVH J5 C21 4 +VS_ES7 VZR9 R27 1K 5.6V BZ1 Buzzer - + C20 2.2uF R24 10K SW_lock SW22 SW_lock 1 Notes: 1. The ESD protection circuits protect most of pins. However pins, V+, V-, AGND, DGND and VR1 are not protected enough because the parasitic effect must be decrease. Therefore enough external protection is needed for assembling, carrying and keeping. In addition, components connecting to these unprotected pins have to be soldered on board before the IC is soldered. 2. All the zener diodes above are used for IC protection. These protections are needed and these zener diodes must be soldered on PCB first before soldering ES51927 on. 3. The OVX pin resistance have to be kept below 120kΩ for the capacitance mode accuracy (6/60nF range). For higher voltage protection, additional configuration of PTC protection is necessary. Ver 2.7 + A 1 7 + C19 1uF ADO SW_lock SW21 A Title Size B Date: File: 10uF ES51927 6000 Counts Smart DMM Number Application Circuit ( TRMS ) Sheet of Drawn By: 6 Revision 30-Aug-2007 D:\Protel file\ES51928 Serial.ddb 2 3 4 5 21 07/10/03 ES51927 6000 Counts Smart DMM Package Information 7.1 100 Pin LQFP Package 7.2 Dimension Parameters Ver 2.7 22 07/10/03