iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 1/9 FEATURES Ë Ë Ë Ë Ë Ë Ë Ë Ë Ë Ë Ë Ë APPLICATIONS Monolithic construction with integrated photodiodes ensures excellent matching and technical reliability Short track spacing of 600 µm Elimination of dark currents through differential scanning Photocurrent amplifier with high cut-off frequency Comparators with precise signal-related hysteresis Current-limited push-pull outputs Adjustable LED current control for constant received power Integrated power driver for the LED LED current monitor with error message output Integrated test aid Low power consumption from 5V supply voltage Available as a 20-pin BLCC or as chip Options: extended temperature range of -40..110 °C, customized packages, reticle assembly Ë Ë Optical position decoding using the principle of differential scanning Incremental and absolute encoder with a resolution of up to 8 bits CHIP 3.05mm × 5.1mm BLOCK DIAGRAM 5V +/- 10% 20 VCC VCC 12 : 1 C1 100nF 1.2V 7 ISET R1 27kΩ 6 AGND C2 100nF 1 CSR LED-CURRENT CONTROL DDC COMPARATOR IP 10 PUSH-PULL OUTPUT S0 NI0 ANALOG OUTPUT DP1 NER DN1 (see TRACK 0) DN2 (see TRACK 0) AMPLIFIER DP3 D1 LED R3 10kΩ ERROR 19 2 TRACK 0 TRACK 1 S1 18 NI1 3 17 S2 DP2 R2 30Ω IN DN0 DP0 5 MONITOR AMPLIFIER AMPLIFIER LED COMPARATOR TRACK 2 PUSH-PULL OUTPUT NI2 4 S3 16 S4 15 S5 14 S6 13 S7 12 GND 11 DN3 TRACK 3 9 DP4 DN4 (see TRACK 3) TRACK 4 DP5 DN5 (see TRACK 3) TRACK 5 DP6 DN6 (see TRACK 3) TRACK 6 DP7 DN7 (see TRACK 3) TRACK 7 TIP c2 1 BIAS TEST 8 TIN c2 1 Copyright © 1999, 2010, iC-Haus iC-OG BLCC OGC 1.2V www.ichaus.com iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 2/9 DESCRIPTION The iC-OG device is an optoelectronic detector IC for linear and angle measuring systems, such as glass scales or shaft encoders, for example. Photodiodes, amplifiers, comparators and TTL-compatible push-pull output drivers are integrated monolithically. Each of the 8 tracks is evaluated differentially; there are also analog outputs available from three of the special feature tracks. The integrated LED current control with a driver stage enables a transmit diode with series resistor to be directly connected and ensures a constant optical received power. The setpoint for the receive current is adjusted using an external resistor. Should the LED current control deviate from its working range, this is reported at the error message output. Two test pins allow a full test of all functions to be carried out excluding the photodiodes. All push-pull and analog outputs are protected against ESD and short-circuit damage. The error message output NER is also protected against short-circuiting and can be used in bus systems due to its open-collector output. iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 3/9 CHIP LAYOUT Dimensions in µm; chip size 3.05 mm × 5.1 mm PAD DESCRIPTION Name Function CSR NI0 NI1 NI2 LED AGND ISET TIN TIP NER GND S7 .. S0 VCC External capacitor for LED control Track 0 Analog Push-Pull Output Track 1 Analog Push-Pull Output Track 2 Analog Push-Pull Output LED Driver Output Reference Ground for ISET and CSR circuitry LED Current Control Setup Negative Test Aid Input Positive Test Aid Input Error Message Output, low active Ground Track 7 Push-Pull Output .. Track 0 Push-Pull Output +5V Supply Voltage iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 4/9 ABSOLUTE MAXIMUM RATINGS Values beyond which damage may occur; device operation is not guaranteed. Item Symbol Parameter Conditions Fig. Unit Min. Max. G001 VCC Supply Voltage -0.3 6 V G301 V(S) Voltage at Outputs S0..7 -0.3 VCC+0.3 V G302 I(S) Current in Outputs S0..7 -3 3 mA G501 V(NI) Voltage at Analog Outputs NI0..2 -0.3 VCC+0.3 V G502 I(NI) Current in Analog Outputs NI0..2 -3 3 mA G601 I(TIP) I(TIN) Current in TIP, TIN -1 1 mA G701 I(ISET) Current in ISET -1 0.1 mA G702 I(AGND) Current in AGND -5 5 mA G703 I(LED) Current in LED V(LED)< 0 or V(LED)> VCC -3 3 mA G704 I(LED) Current in LED 0< V(LED) < VCC 0 150 mA V(S)< 0V or V(S)> VCC G705 V(CSR) Voltage at CSR -0.3 VCC+0.3 V G706 I(CSR) Current in CSR -3 3 mA GA01 V(NER) Voltage at NER -0.3 6 V E001 Vd() ESD Susceptibility 2 kV TG1 Tj Junction Temperature 125 °C TG2 Ts Storage Temperature HBM, 100 pF discharged through 1.5 kΩ -40 see package specification THERMAL DATA Operating Conditions: VCC= 5V ±10% Item Symbol Parameter Conditions Ta Operating Ambient Temperature Range see package specification Fig. Unit Min. T1 All voltages are referenced to ground unless otherwise noted. All currents into the device pins are positive; all currents out of the device pins are negative. Typ. Max. iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 5/9 ELECTRICAL CHARACTERISTICS Operating Conditions: VCC= 5V ±10%, Tj= -40..125 °C, unless otherwise noted. Item Symbol Parameter Conditions Tj EC Fig. Unit Min. Typ. Max. Total Device 001 VCC Permissible Supply Voltage Range 4.5 002 I(VCC) Supply Current in VCC, Outputs S0..7 hi LED control active: R(ISET/AGND)= 140kΩ, I(LED). 8mA, NER=hi; I(DP0..7)= 30nA, I(DN0..7)= 3nA, I(S0..7)= 0; 10 mA 003 I(VCC) Supply Current in VCC, Outputs S0..7 lo LED control active: R(ISET/AGND)= 14kΩ, I(LED). 80mA, NER=hi; I(DP0..7)= 3nA, I(DN0..7)= 30nA, I(S0..7)= 0; 10 mA 004 fo Cut-off Frequency, tracks 0..7 sinusoidal waveform, I(DP0..7)= 3..30nA I(DN0..7)= 30..3nA 005 tp(D-A) Propagation Delay see No. 4 006 Cut-off Frequency, tracks 0..7 sinusoidal waveform, I(DP0..7)= 6..60nA I(DN0..7)= 60..6nA 007 Propagation Delay see No. 6 5.5 100 V kHz 2.5 200 µs kHz 1.5 µs Photodiodes and Amplifiers, tracks 0..7 101 Aph(D) Radiant Sensitive Area 102 S(λ)max Spectral Sensitivity λ= 850nm 103 λar Range of Spectral Sensitivity S(λar)= 0.1×S(λ)max 104 I(D) Permissible Photocurrent 105 CM() Common Mode DPi to DNi 0.2 × 0.3 mm² 0.5 500 A/W 1050 nm 90 nA 0.85 1 1.15 8 11 17 % 0.95 V V 1.05 V V 0.4 V V Difference Comparators, tracks 0..7 201 Hys Hysteresis referred to [I(DPi) + I(DNi)] /2 I(DPi, DNi)= 3..90nA Push-Pull Outputs S0..7 301 302 303 Vs()hi Vs()hi Vs()lo Saturation Voltage hi Saturation Voltage hi Saturation Voltage lo Vs()hi= VCC-V(); I()= -40µA 27 0.69 27 0.83 27 0.22 Vs()hi= VCC-V(); I()= -400µA I()= 1.6mA 304 Isc()hi Short-Circuit Current hi V()= 0V..VCC-1.2V -7 -4.6 -1.4 mA 305 Isc()lo Short-Circuit Current lo V()= 0.4V..VCC 1.8 7.3 13 mA 306 tr() Slew-Rate hi CL()= 30pF 130 V/µs V/µs 380 V/µs V/µs 24 27 307 tf() Slew-Rate lo CL()= 30pF 61 40 27 115 308 Vc()hi Clamp Clamp Voltage hi Vc()hi= V()-VCC; S()= hi, I()= 3mA 0.4 1.5 V 309 Vc()lo Clamp Clamp Voltage lo S()= lo, I()= -3mA -1.5 -0.4 V iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 6/9 ELECTRICAL CHARACTERISTICS Operating Conditions: VCC= 5V ±10%, Tj= -40..125 °C, unless otherwise noted. Item Symbol Parameter Conditions Tj EC Fig. Unit Min. Typ. Max. Analog Outputs NI0..2 501 CR() Current Ratio I(NIi) / (I(DPi)-I(DNi)) V(NIi)= 0.3V..VCC-1.2V, I(DPi)= 3..90nA, I(DNi)= 90..3nA 550 27 1250 720 502 I0() Leakage Current V(NI)= 0.3V..VCC-1.2V, I(DPi,DNi)= 0 -1.5 1.5 503 fo() Cut-off Frequency V(NIi)= constant, sinussoidal waveform, I(DPi)= 3..30nA, I(DNi)= 30..3nA 100 kHz 504 fo() Cut-off Frequency V(NIi)= constant, sinussoidal waveform, I(DPi)= 6..60nA, I(DNi)= 60..6nA 200 kHz 505 fo() Cut-off Frequency R(VCC/NIi)= 50kΩ, R(NIi/GND)= 50kΩ, CL()= 30pF 50 506 Vc()hi Clamp Voltage hi Vc()hi= V()-VCC; I()= 3mA 0.4 1.5 V 507 Vc()lo Clamp Voltage lo I()= -3mA -1.5 -0.4 V 750 80 µA kHz Test Aid TIP, TIN 601 CR() Current Ratio I(TIP) / I(DPi,DDC) and I(TIN) / I(DNi) Test aid active, I()= 2..200µA 602 It() Pull-Down Current (Test Aid Turn-on Threshold) V()= 0.4V Turn-on Voltage Test aid active, I(TIP)= 2..200µA and I(TIN)= 100µA, or I(TIP)= 100µA and I(TIN)= 2..200µA 603 V()on 1100 2.5 -40 27 85 125 -40 27 85 125 1600 125 µA µA µA µA µA 2.7 2.4 2.1 1.9 V V V V 360 nA 14 19 25 28 1.9 1.6 1.2 1.1 2.4 2.1 1.8 1.6 LED Current Control ISET, AGND, LED, CSR 701 ISUM Permissible Sum Current of photodiodes DP0, DN0, DP1, DN1 702 I(LED) Permis. Driver Current in LED 703 Vs(LED) Saturation Voltage at LED ISUM= I(DP0) +I(DN0) +I(DP1) +I(DN1) 0 0 I(LED)= 80mA, I(ISET)> 20µA, V(CSR)= VCC 704 V(ISET) Voltage at ISET R(ISET/AGND)= 10..150kΩ 705 CR() Current Ratio I(ISET) / I(CSR) V(CSR)= 0.3V, ISUM= 0, R(ISET)= 10..150kΩ -40 27 85 125 80 mA 1.35 V V V V V 1.35 V 0.96 0.88 0.79 0.72 1.15 1.22 8 -40 27 85 125 15 12.0 11.9 11.75 11.65 706 CR() Current Ratio I(CSR) / ISUM V(CSR)= 1..3V, I(ISET)= 0 70 92 130 707 Vc()hi Clamp Voltage hi at ISET, LED, CSR Vc()hi= V()-VCC; I()= 3mA 0.4 1.5 V 708 Vc()lo Clamp Voltage lo at ISET, LED, CSR VCC= 0V, I()= -3mA -1.5 -0.4 V iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 7/9 ELECTRICAL CHARACTERISTICS Operating Conditions: VCC= 5V ±10%, Tj= -40..125 °C, unless otherwise noted. Item Symbol Parameter Conditions Tj EC Fig. Unit Min. Typ. Max. 0.4 V 27 mA 10 µA Control Monitor NER 801 Vs() Saturation Voltage lo I(NER)= 3.2mA 0.27 802 Isc() Short-Circuit Current lo V(NER)= VCC 15 803 I0() Collector Off-state Current NER: off, V(NER)= 0..6V DESCRIPTION OF FUNCTIONS LED current control The integrated LED current control with a driver stage controls the LED in accordance with the sum of the photocurrents from the tracks 0 and 1. Compensation is made for age and dirt, as well as for the reduced efficiency of the LED caused by rises in temperature. Fig. 1: LED Current Control and Monitoring The photodiodes DPO, DNO, DP1 and DN1 act as reference diodes. The sum is output via a current sink to the comparison point pin CSR. Simultaneously, the resistor R1 at pin ISET (the voltage at the ISET pin is kept at a constant of approximately 1.22V) supplies a reference current for the current source from VCC, which also works towards the comparison point pin CSR. The comparison point also receives the amplified current from the compensation diode DDC in order to compensate for dark currents and for the amplifier input currents. If there is an optical feedback from the LED to the reference photodiodes, the voltage at the CSR pin adjusts to satisfy the needs of the power driver for the required transmit current at pin LED. In this instance, the voltage ratio between I(ISET) and the sum of the photodiode current ISUM is constant (Electrical Characteristics Nos. 706 and 707). The current flowing through the resistor R1 is the setpoint for the control and directly presets the desired level of illumination. An internal capacitor ensures that the control is stable. The comparison point pin CSR is lead out in the BLCC20 package, enabling an external capacitor C2 to be connected to adapt the control behaviour. Lower values for R1 require larger values for C2, which also improve the power-supply rejection ratio for the control. Values from 10nF upwards are recommended. iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 8/9 A resistor in series with the LED limits the current in pin LED and sets the operating limits of the control. The optical feedback between the LED and the reference photodiodes should be good enough to establish an LED current of less than 15mA at room temperature. Only under these conditions does the power driver have a sufficient current reserve to correct the LED's decline in efficiency even at high temperatures. Control Monitor and Error Message Output The control monitor observes the potential at the CSR pin. Voltages which bring the power driver to saturation or off-state are recognized and indicated at the open-collector output by NER= low. APPLICATIONS INFORMATION Using the test aid The threshold current defined in the electrical characteristic No. 602 must be exceeded at both pins TIP and TIN simultaneously to activate the iC-OG's built-in test aid. Once it has been activated, the test aid does not switch back to off-state until the current drops below approx. 1µA. A clamp circuit as shown in Figure 2 also prevents falling below the test aid turn-on threshold for a short time. The output polarity of the iC-OG is to be changed over with the switch. Fig. 2: Wiring the test aid This specification is for a newly developed product. iC-Haus therefore reserves the right to change or update, without notice, any information contained herein, design and specification; and to discontinue or limit production or distribution of any product versions. Please contact iC-Haus to ascertain the current data. Copying -- even as an excerpt -- is only permitted with iC-Haus approval in writing and precise reference to source. iC-Haus does not warrant the accuracy, completeness or timeliness of the specification on this site and does not assume liability for any errors or omissions in the materials. The data specified is intended solely for the purpose of product description. No representations or warranties, either express or implied, of merchantability, fitness for a particular purpose or of any other nature are made hereunder with respect to information/specification or the products to which information refers and no guarantee with respect to compliance to the intended use is given. In particular, this also applies to the stated possible applications or areas of applications of the product. iC-Haus conveys no patent, copyright, mask work right or other trade mark right to this product. iC-Haus assumes no liability for any patent and/or other trade mark rights of a third party resulting from processing or handling of the product and/or any other use of the product. As a general rule our developments, IPs, principle circuitry and range of Integrated Circuits are suitable and specifically designed for appropriate use in technical applications, such as in devices, systems and any kind of technical equipment, in so far as they do not infringe existing patent rights. In principle the range of use is limitless in a technical sense and refers to the products listed in the inventory of goods compiled for the 2008 and following export trade statistics issued annually by the Bureau of Statistics in Wiesbaden, for example, or to any product in the product catalogue published for the 2007 and following exhibitions in Hanover (Hannover-Messe). We understand suitable application of our published designs to be state-of-the-art technology which can no longer be classed as inventive under the stipulations of patent law. Our explicit application notes are to be treated only as mere examples of the many possible and extremely advantageous uses our products can be put to. iC-OG 8-BIT DIFFERENTIAL SCANNING OPTO ENCODER Rev C1, Page 9/9 ORDERING INFORMATION Type Package Order designation iC-OG iC-OG BLCC OGC iC-OG Chip iC-OG BLCC OGC For technical support, information about prices and terms of delivery please contact: iC-Haus GmbH Am Kuemmerling 18 D-55294 Bodenheim GERMANY Tel +49-6135-9292-0 Fax +49-6135-9292-192 http://www.ichaus.com E-mail [email protected] Appointed local distributors: http://www.ichaus.de/support_distributors.php