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LOW LEVEL MEASURE & SOURCE www.keithley.com 1.888.KEITHLEY (U.S. only) A Greater Measure of Confidence

6514 Programmable Electrometer

The Model 6514 Electrometer combines flexible interfacing capabilities with current sensitivity, charge measure men t capabilities, resolution, and speed that are equal or superior to our earlier electrometers The Model 6514’s built-in IEEE-488, RS-232, and digital I/O interfaces make it simple to c onfigure fully automated, high speed systems for low-level testing . T he 5½-digit Model 6514 is designed for applica- tions that demand fast, yet precise measurements of low currents, voltages from high resistance sources, charges, or high resistances T he Model 6514’s exceptional measurement perfor- mance comes at an affordable price . While its cost is comparable with that of many high end DMMs, the Model 6514 offers far greater current sensitivity and sig n ificantly lower voltage burden (as low as 20µV) than other instruments can provide . D on a bu dget The Model 6514 offers the flexibility and sensitivity needed for a wide array of experiments, provid - ing better data far faster than older electrometer designs . Applications include measuring currents from light detectors and other sensors, beam experiments, and measuring resistances using a current source In addition to use by researchers in areas such as physics, optics, and materials science, the Model 6514’s affordable price makes it an attractive alternative to high end DMMs for low current measurement applications, such as testing resistance and leakage current in switches, relays, and other components For more information on how the Model 6514 does this, refer to the section titled “Low Voltage Burden .” T he Model 6514 builds on the features and capabilities of the Keithley electrometers that preceded it For example, like those instruments, a built-in constant current source simplifies measuring resistance T wo analog outputs—a 2V output and a preamp output—are available for recording data with strip- chart recorders .

  • < 1f a n oise
  • > 200TW input impedance on voltage measurements
  • C harge measurements from 10fC to 20µC
  • H igh speed—up to 1200 readings/second
  • In terfaces readily with switches, computers, and component handlers
  • C ancels voltage and current offsets easily or dering Information

6514 Programmable

a ccessories s upplied 237- alG l ow Noise Triax Cable, 3-sl ot Triax to al ligator Clips, 2m (6.6 ft) aC CE ssorI E s aVaIl ablE CablEs 237-ALG-2 L ow Noise Triax Cable, 3-Slot Triax to Alligator Clips 7007-1 S hielded IEEE-488 Cable, 1m (3 .3 f 7007-2 S hielded IEEE-488 Cable, 2m (6 .6 f 7009-5 R S-232 Cable 7078-TRX-3 L ow Noise Triax Cable, 3-Slot Triax Connectors, 0 .9 m (3 ft) 7078-TRX-10 L ow Noise Triax Cable, 3-Slot Triax Connectors, 3m (10 ft) 7078-TRX-20 L ow Noise Triax Cable, 3-Slot Triax Connectors, 6m (20 ft) 8501-1 T rigger-Link Cable, 1m (3 .3 f 8501-2 T rigger-Link Cable, 2m (6 .6 f raCK M ouNT KITs 4288-1 S ingle Fixed Rack Mounting Kit 4288-2 D ual Fixed Rack Mounting Kit aDa PTE rs 7078-TRX-BNC 3 -Lug Triax to BNC Adapter 237-TRX-NG T riax Male-Female Adapter with Guard Disconnected 237-TRX-T -Slot Male Triax to Dual 3-Lug Female Triax Tee Adapter 237-TRX-TBC -Lug Female Triax Bulkhead Connector (1 .1 kV rated) 7078-TRX-TBC -Lug Female Triax Bulkhead Connector with Cap GPIb INTE rfaCEs KPCI-488LPA I EEE-488 Interface/Controller for the PCI Bus KUSB-488B I EEE-488 USB-to-GPIB Interface AdaptersEr VICEs aVaIl ablE 6514-3Y-EW 1 -year factory warranty extended to 3 years from date of shipment C/6514-3Y-ISO 3 ( ISO-17025 accredited) calibrations within 3 years of purchase* TRN-LLM-1-C C ourse: Making Accurate Low-Level Measurements *Not available in all countries Fast, precise current, charge, voltage, and resistance measurements Fast, precise current, charge, voltage, and resistance measurements

LOW LEVEL MEASURE & SOURCE A Greater Measure of Confidence www.keithley.com 1.888.KEITHLEY (U.S. only) Economical Component Testing Once, electrometers were simply considered too slow to keep up with the high throughput that production test applications demand The Model 6514 is designed for fast, sensitive measurements, providing speeds up to 1200 readings per second with fast integration or 17 measurements per second with 60Hz line-cycle integration It offers 10fA resolution on 2nA signals, settling to within 10% of the final value in just 15ms . A normal-mode rejec- tion ratio (NMRR) of 60dB allows making accurate low current measure - ments, even in the p resence of line frequency induced currents, which is a common concern in production floor environments . The instrument’s sen- sitivity makes it easy to determine the leakage resistance on capacitances up to 10nF or even on h igher capacitances when a series resistor is used W hile the Model 6514 can be easily operated manually using the front panel controls, it can also be externally controlled for automated test

applications

Built-in IEEE-488 and RS -2 32 interfaces make it possible ID

6514 Electrometer

IL = 0 Photodiode (no incident light) VBURDEN CAL VOFFSET Total offset voltage = 0 A/D fi gure 2. D ark Current Measurement with b urden Voltage Corrected Leakage Resistance RL IL (error current due to VBURDEN) Photodiode (no incident light) VBURDEN A/D ID Electrometer fi gure 1. D ark Current Measurement with b urden Voltage un corrected to program all instrument functions over the bus through a computer controller . The instrument’s interfaces also simplify integrating external hardware, such as sources, switching systems, or other instruments, into the test system . A digital I/O interface can be used to link the Model 6514 to many popular component handlers for tight systems integration in bin - ning, sorting, and similar applications . T hese features make the Model 6514 a powerful, low cost tool for systems designed to test optical devices and leakage resistance on low-value capaci - tors, switches, and other devices, particularly when the test system already includes a voltage source or when the source current/measure voltage technique is used to determine r esistance . l ow Voltage b urden The Model 6514’s feedback ammeter design minimizes voltage offsets in the input circuitry, which can affect current measurement accuracy The instrument also allows active cancellation of its input voltage and current offsets, either manually via the front panel controls or over the bus with IEEE-488 commands D ark Current Measurements When measuring dark currents ( Figure 1) from a device such as a photodiode, the ammeter reads the sum of two different currents . The first current is the dark current (I D) generated by the detector with no light falling upon the device (in other words, the signal of interest); the second one is the leakage current (I L) generated by the voltage burden (V BURDEN ) appearing at the terminals of the ammeter . In a feedback ammeter, the primary “voltage burden” is the amplifier offset voltage . This leakage current represents an error current Without the use of cancellation techniques, IL = VBURDEN/RL . F igure 2 illustrates how the Model 6514’s CAL VOFFSET is adjusted to cancel VBURDEN to within the voltage noise level of a few microvolts, so the measured current is only the true dark current D) of the photodiode . In a similar manner, offset currents can also be cancelled Earlier electrometers used an internal numerical correction technique in which the voltage burden was still present, so the measured dark current included the error term I L = VBURDEN/R L . V oltage b urden and Measurement Error Electrometers provide current measurement with lower t erminal voltage than is possible when making DMM meas u rements . As shown in Figure 3, DMMs measure current using a shunt resistance that develops a voltage (typically 200mV full-range) in the input circuit This creates a terminal voltage (VBURDEN ) of about 200mV, thereby lowering the measured current . E lectrometers reduce this terminal v oltage by using the feedback ammeter configuration i llustrated in Figure 1 . The Model 6514 lowers this terminal voltage still further—to the level of the voltage noise—by canceling out the small offset voltage that remains, as shown in Figure 2 Any error signals that remain are n egligible in comparison to those that can occur when me asuring current with a DMM . Fast, precise current, charge, voltage, and resistance measurements Fast, precise current, charge, voltage, and resistance measurements

LOW LEVEL MEASURE & SOURCE www.keithley.com 1.888.KEITHLEY (U.S. only) A Greater Measure of Confidence – A/D R VBURDEN = 200mV at full range Desired Current Reading: I = VSOURCE R DMM’s Actual Current Reading: I = VSOURCE – VBURDEN R DMM I fi gure 3. Errors Due to bu rden Voltage when Measuring with a DMM Vo l Ts a cc uracy T emperature (1 Year)1 C oefficient r a nge re solution ± (%rdg+counts) ± (%rdg+counts)/°C 2 V 1 0 µ V 0 .0 25 + 4 0 .0 03 + 2 0 V µ V 0 .0 + 3 0 .0 02 + 1 00 V m V 0 .0 + 3 0 .0 02 + 1 NoT E s 1 . W hen properly zeroed, 5 ½-digit . Rate: S low (100ms integration time) . NMRR: 60dB on 2V, 20V, >55dB on 200V, at 50Hz or 60Hz ±0 .1 % . C MRR: >120dB at DC, 50Hz or 60Hz . I NPUT IMPEDANCE: >200TW in parallel with 20pF, <2pF guarded (10M W with zero check on) . S MALL SIGNAL BANDWIDTH AT PREAMP OUTPUT: Typically 100kHz (–3dB) . aM P s acc uracy T emperature (1 Year)1 C oefficient r a nge re solution ± (%rdg+counts) ± (%rdg+counts)/°C 2 0 p A 1 00 a A2 1 + 3 0 0 .1 + 5 p A f A2 1 + 5 0 .1 + 1 n A f A 0 .2 0 .1 + 2 n A f A 0 .2 0 .0 + 1 n A p A 0 .2 0 .0 + 1 µ A p A 0 .1 0 .0 + 2 µ A p A 0 .1 0 .0 + 1 µ A n A 0 .1 0 .0 + 1 m A n A 0 .1 0 .0 + 2 m A n A 0 .1 0 .0 + 1 NoT E s 1 . W hen properly zeroed, 5½-digit . Rate: S low (100ms integration time) . 2 . aA =10–18A, f A=10–15A . INPUT BIAS CURRENT: <3fA at T CAL (user adjustable) . Temperature coefficient = 0 .5 fA/°C . I NPUT BIAS CURRENT NOISE: <750aA p-p (capped input), 0 .1 Hz to 10Hz bandwidth, damping on . Digital filter = 40 readings . I NPUT VOLTAGE BURDEN at T CAL ±1°C (user adjustable) : <20µV on 20pA, 2nA, 20nA, 2µA, 20µA ranges . <100µV on 200pA, 200nA, 200µA ranges . <2mV on 2mA range . <4mV on 20mA range . T EMPERATURE COEFFICIENT OF INPUT VOLTAGE BURDEN: <10µV/°C on pA, nA, µA ranges . P REAMP SETTLING TIME (to 10% of final value): 2 .5 s typical on pA ranges, damping off, 3s typi - cal on pA ranges damping on, 15ms on nA ranges, 5ms on µA and mA ranges . N MRR: >95dB on pA, 60dB on nA, µA, and mA ranges at 50Hz or 60Hz ±0 .1 % . Digital Filter = 40 . oHMs a c cu ra cy T emperature ( 1 Year)1 C oefficient T est 5½-Digit 1 8°–28°C 0 °–18°C & 28°–50°C C urrent r a nge r e solution ± (% rdg+counts) ± (% rdg+counts)/°C ( nominal) 2 kW 10 mW 0 .2 0 + 1 0 0 .0 1 + 2 0 .9 m A kW 0 mW 0 .1 0 .0 + 1 0 .9 m A kW W 0 .2 0 .0 + 1 0 .9 m A MW 10 W 0 .2 0 .0 + 2 0 .9 µ A MW 0 W 0 .2 0 .0 + 1 0 .9 µ A MW kW 0 .3 0 .0 + 1 0 .9 µ A GW kW 1 .5 0 .0 + 2 0 .9 n A GW 0 kW 1 .5 0 .0 + 1 0 .9 n A GW MW 1 .5 0 .0 + 1 0 .9 n A NoT E s 1 . W hen properly zeroed, 5½-digit . Rate: S low (100ms integration time) . MAXIMUM O PEN C IRCUIT V OLTAGE: 250V DC . P REAMP S ETTLING T IME (To 10% of final reading with <100pF input capacitance): 2k W through 200k W: 2ms; 20MW through 200M W: 90ms . 2GW through 200G W: 1s . The example below compares a DMM’s voltage burden errors with the 6514’s . D MM of fset Currents Typically, offset currents in DMMs are tens or hundreds of picoamps, which severely limits their low current measuring capabilities compared to the Model 6514 with 3fA input bias current If: The desired current reading is: I = 1V 50kW = 20µA VSOURCE = 1V , R = 50kW Actual Reading (20µA range on DMM): I = 1V – 200mV 50kW = 800mV 50kW = 16µA = 20% Burden error with a DMM VBURDEN = 200mV

6514 Actual Reading:

I = 0 .999990V 50kW = 19 .9998µA = 0.001% Burden error with the 6514 VBURDEN = 10µV Refer to Figure 3. Refer to Figure 2. aPP lI C aT I oNs

  • H igh resistivity measurements
  • l eakage currents
  • I on selective electrode measurements
  • p H measurements
  • C onductivity cells
  • P otentiometry Model 6514 specifications Model 6514 specifications

LOW LEVEL MEASURE & SOURCE A Greater Measure of Confidence www.keithley.com 1.888.KEITHLEY (U.S. only) OVERRANGE INDICATION: Display reads “OVRFLOW .” R ANGING: Automatic or manual . C ONVERSION TIME: Selectable 0 1PLC to 10PLC . P ROGRAMS: Provide front panel access to IEEE address, choice of engineering units or s cientific notation, and digital calibration MAXIMUM INPUT: 250V peak, DC to 60Hz sine wave; 10s per minute maximum on mA ranges . MAXIMUM COMMON MODE VOLTAGE (DC to 60Hz sine wave): Electrometer, 500V peak . I SOLATION (Meter COMMON to chassis): Typically 1010W in parallel with 500pF . I NPUT CONNECTOR: Three lug triaxial on rear panel . V ANALOG OUTPUT: 2V for full range input . Inverting in Amps and Coulombs mode . Output impedance 10k W . P REAMP OUTPUT: Provides a guard output for Volts mea s ure m ents . Can be used as an inverting output or with external feedback in Amps and Coulombs modes . D IGITAL I NTERFACE : Handler Interface: Start of test, end of test, 3 category bits . Digital I/O: 1 Trigger input, 4 outputs with 500mA sink capability . Connector: 9 pin D s ubminiature, male pins . E MC: Conforms with European Union Directive 89/336/EEC EN55011, EN50082-1, EN61000-3-2, EN61000-3-3, FCC part 15 class B . S AFET y : Conforms with European Union Directive 73/23/EEC EN61010-1 . GUA RD: Switchable voltage and ohm guard available . T RIGGER LINE: Available, see manual for usage . RE ADING STORAGE: 2500 readings . R EADING RATE: To internal buffer 200 readings/second 1 To IEEE-488 bus 00 readings/second 1, 3 To front panel 1 7 readings/second at 60Hz; 2 5 readings/second at 50Hz .2 N otes: 1 0 .0 1PLC, digital filters off, front panel off, auto zero off . 2 1 .0 0PLC, digital filters off . 3 Binary transfer mode . D IGITAL FILTER: Median and averaging (selectable from 2 to 100 readings) . D AMPING: U ser selectable on Amps function . EN VIRONMENT: Operating: 0°–50°C; relative humidity 70% non-condensing, up to 35°C . Storage: –25° to +65°C . W ARM-UP: 1 hour to rated accuracy (see manual for recommended procedure) . P OWER: 90–125V or 210–250V, 50–60Hz, 60VA . P HySI CAL: Case Dimensions: 90mm high × 214mm wide × 369mm deep (3 ½ in . × 83 ⁄8 in . × 149 ⁄16 in . ) . Working Dimensions: From front of case to rear including power cord and IEEE-488 con - nector: 15 .5 i nches . N et Weight: <4 .6 kg (<10 .1 lbs) . S hipping Weight: <9 .5 kg (<21 lbs) . IEEE-488 bus IMPl EMENTaTI o N MULTILINE COMMANDS: DCL, LLO, SDC, GET, GTL, UNT, UNL, SPE, SPD . IM PLEMENTATION: SCPI (IEEE-488 .2 , SCPI-1996 .0 ); DDC (IEEE-488 .1 ) . UN ILINE COMMANDS: IFC, REN, EOI, SRQ, ATN I NTERFACE FUNCTIONS: SH1, AH1, T5, TE0, L4, LE0, SR1, RL1, PP0, DC1, DT1, C0, E1 . PROGRAMMABLE PARAMETERS: Function, Range, Zero Check, Zero Correct, EOI (DDC mode only), Trigger, Terminator (DDC mode only), Data Storage 2500 Storage, Calibration (SCPI mode only), Display Format, SRQ, REL, Output Format, Guard, V-offset Cal, I-offset Cal . ADDRESS MODES: TALK ONLY and ADDRESSABLE . L ANGUAGE EMULATION: 6512, 617, 617-HIQ emulation via D DC m ode . T RIGGER TO READING DONE: 150ms typical, with external trigger . R S-232 IMPLEMENTATION: Supports: SCPI 1996 .0 . B aud Rates: 300, 600, 1200, 2400, 4800, 9600, 19 .2 k, 38 .4 k, 57 .6 k . Protocols: Xon/Xoff, 7 or 8 bit ASCII, parity-odd/even/none . Connector: DB-9 TXD/RXD/GND . Cou lo Mbs a cc uracy T emperature ( 1 Year)1, 2 Coefficient r a nge re solution ± (%rdg+counts) ± (%rdg+counts)/°C 2 0 nC 1 0 f C 0 .4 + 5 0 0 .0 4 + 10 00 nC f C 0 .4 + 5 0 .0 4 + 10 2 µ C p C 1 + 5 0 .0 5 + 10 0 µC p C 1 + 5 0 .0 5 + 10 Notes: 1 . C harge acquisition time must be <1000s, derate 2% for each additional 10,000s . 2 . W hen properly zeroed, 6½-digit . Rate: S low (100ms integration time) . INPUT BIAS CURRENT: <4fA at T CAL . Temperature coefficient = 0 .5 fA/°C . Model 6514 rear panel Model 6514 specifications Model 6514 specifications