iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 1/8 FEATURES APPLICATIONS ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ CW operation up to 90 mA from 2.4 to 6 V supply voltage Rapid soft start after power-on typical within 70 µs Simple power adjustment via the external resistor Control loop accuracy better than 1% with changes in temperature, supply voltage and load current Integrated reverse polarity protection for the iC and laser diode Strong suppression of transients with very small external capacitors; integrated flyback path Permanent shutdown with excessive temperature and overcurrent (i.e. if the laser diode is damaged or the feedback current path fails) Two feedback inputs permit all current LD types to be used (N/P/M configurations) Modulation via the feedback inputs is possible Wide monitor current range from 10 µA to 2.5 mA iC-WK with additional spike detection at monitor input MDA Battery-powered LD modules LD Pointers Laser levels Bar-code readers PACKAGES SO8 MSOP8 BLOCK DIAGRAM +2.4..+6 V 6 VCC LDA 7 CVCC CLDA ..47 nF.. ..1 uF.. TRANSIENT PROTECTION − iC−WKL 1 MDK 4 MDA 5 MD LD + VREF 0.5 V CI D LDK 2 8 NQ R CI RM 200..50 k Ω OVERCURRENT/ OVERTEMP. 1 GND iC−WK FEEDBACK MON. GND ..100 nF.. AGND CM 47 pF 3 suitable laser diode configurations: N, P, M MD MD Copyright © 2006 iC-Haus LD LD LD MD http://www.ichaus.com iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 2/8 DESCRIPTION The iC-WK/L device is a driver for laser diodes in continuous wave operation which requires only four external components. The wide power supply range of 2.4 to 6 V and the integrated reverse battery protection allow for battery operation with a minimum of two cells. A reversed battery connection destroys neither the iC nor the laser diode. CI determines the control time constants and start-up time. The iC includes integrated circuitry protecting against destruction by ESD, excessive temperature and overcurrent and a soft start which regulates the power and protects the laser diode when the power supply is switched on. The iC also filters the laser diode power supply for transients. In the event of failure, such as overcurrent in the laser path with a lack of feedback, for example, a quick power lockout is activated. The shutdown continues until power is reapplied, permitting a restart. The strain on power packs and batteries is relieved and the laser class is retained even in the event of a disturbance. The power supply is regulated and adapted to the laser diode used by an external resistor at MDA. The monitor current acts as a reference and is regulated independent of the influence of temperature and supply voltage (range: 10 µA to 2.5 mA). The capacitor at A second monitor input, pin MDK, allows the driver to be used for other types of laser diode configuration; alternatively, it can be used as an analogue modulation input (DC to a few kHz). iC-WK offers additional protection by means of spike detection at pin MDA. Should spikes or oscillation occur at pin MDA the power lockout is activated. PACKAGES SO8, MSOP8 to JEDEC PIN CONFIGURATION SO8 (top view) PIN FUNCTIONS No. Name Function 1 8 2 7 LDK GND LDA CI 4 WK code... ... 3 AGND 6 VCC 5 MDA MDK PIN CONFIGURATION MSOP8 (top view) AGND MDK iC−WK Code CI GND CI AGND MDK 5 MDA 6 VCC 7 LDA 8 LDK Ground Capacitance for Power Control Reference Ground for CI, RM Monitor Input 2 (MD Cathode, Modulation) APC Setup, Monitor Input 1 (MD Anode) +2.4 to +6 V Supply Voltage Laser Supply (LD Anode) Driver Output (LD Cathode) Do not short-circuit pins AGND and GND, for this may deteriorate the precision of the regulator and interfere with the soft-start! 1 GND 1 2 3 4 LDK LDA VCC MDA iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 3/8 ABSOLUTE MAXIMUM RATINGS No Destruction, correct function not guaranteed. Item No. Symbol Parameter Conditions Fig. Unit Min. Max. G001 VCC Voltage at VCC -6 6.5 V G002 I(VCC) Current in VCC -10 95 mA G003 I(CI) Current in CI -10 10 mA G004 I(LDA) Current in LDA -95 10 mA G005 I(LDK) Current in LDK -10 95 mA G006 I(MDA) Current in MDA -10 10 mA G007 I(MDK) Current in MDK -10 10 mA G008 I(AGND) Current in AGND -10 10 mA G009 I(GND) Current in GND -95 10 mA G010 Vd() ESD Susceptibility at all pins 2 kV G011 Tj Operting Junction Temperature -40 150 °C G012 Ts Storage Temperature Range -40 150 °C MIL-STD-833, method 3015, HBM 100 pF unloaded over 1.5 kΩ THERMAL DATA Operating Conditions: VCC = 2.4...6 V Item No. Symbol Parameter Conditions Fig. Unit Min. T01 Ta Operating Ambient Temperature Range T02 Rthja Thermal Resistance Chip/Ambient -40 SMD assembly, no additional cooling areas All voltages are referenced to ground unless otherwise stated. All currents into the device pins are positive; all currents out of the device pins are negative. Typ. Max. 85 °C 140 K/W iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 4/8 ELECTRICAL CHARACTERISTICS Operating Conditions: VCC = 2.4...6 V, RM = 200 Ω...50 kΩ, Tj = -40...125 °C unless otherwise noted Item No. Symbol Parameter Conditions Tj °C Fig. Unit Min. Typ. Max. Total Device 001 002 VCC Permissible Supply Voltage I(LDK)m Permissible Laser Drive Current (closed control loop) 003 Idc(VCC) Supply Current without load path closed control loop, I(MDK) = 0 004 Ioff(VCC) Supply Current on Reset 005 006 Ir(VCC) Reverse Supply Current RM = 50 kΩ, VCC = -6 V ton() Turn-on Delay VCC: 0 → 5 V to 95 % I(LDK), I(LDK) = I(LDK)m; CI = 47 nF CI = 100 nF 007 Vc()hi 008 009 Clamp Voltage hi at VCC, LDA, MDK Tj = -40...125 °C Tj = -40...80 °C 2.4 6 V 5 5 70 90 mA mA 2.4 5.5 mA 2.4 5 mA -6 -3 mA 70 150 µs µs I() = 10 mA, other pins open 6 9 V Vc(LDK)hi Clamp Voltage hi at LDK V() < VCC + 1 V; I() = 10 mA, other pins open 6 9 V Vc(MDA)hi Clamp Voltage hi at MDA I() = 10 mA, other pins open iC-WKL iC-WK 6 1.1 9 4 V V 4 V 010 Vc()hi Clamp Voltage hi at CI I() = 10 mA, other pins open 1.1 011 Vc()lo Clamp Voltage lo at VCC, LDA, MDK, MDA, CI I() = -10 mA, other pins open -9 V Reference and Monitor Inputs MDA, MDK, AGND 101 V(MDA) Reference Voltage at MDA closed control loop, V(LDK) > Vs(LDK) 102 dV(MDA) Reference Voltage Temperature Drift at MDA see 101; 103 Ierr(MDA) Input Current in MDA closed control loop, I(MDK) = 0 104 dI(MDA) Input Current Temperature Drift in see 103; MDA 105 APCerr Control Error RM = 10 kΩ, Tj = 0...80 °C RM = 10 kΩ, Tj = -40...125 °C 106 dI(MD) Supply Voltage Suppression of monitor current V(VCC): 2.4 → 6 V, I(LDK) = 70 mA 107 Rgnd() Resistor AGND-GND 108 Vf(MDK) Voltage at MDK 109 CR() 110 TC() 480 500 520 mV 120 µV/°C -300 300 nA -2 2 nA/°C 0.3 1 % % -1 1 % 3 Ω Vf() = V(LDA) − V(MDK); I(MDK) = 1 µA...1 mA 0.46 2.1 V Current Ratio I(MDA)/I(MDK) I(MDK) = 10...500 µA I(MDK) = 500 µA...2.5 mA 0.975 0.95 1.025 1.05 Current Ratio Temperature Coefficient I(MDA) / I(MDK) I(MDK) = 10...500 µA I(MDK) = 500 µA...2.5 mA -0.005 -0.025 0.005 0.025 %/°C %/°C 300 400 400 mV mV mV 1 % 300 300 mA mA 85 170 60 130 µs µs µs µs Laser Drive LDA, LDK 201 Vs(LDK) Saturation Voltage at LDK I(LDK) = 40 mA I(LDK) = 70 mA, Tj = -40...125 °C I(LDK) = 90 mA, Tj = -40...80 °C 202 dI(MD) Load Balancing Error I(LD) = 20 mA, I(LDK): 20 mA → 70 mA -1 203 It(LDK) Overcurrent Threshold in LDK Tj = -40...125 °C Tj = -40...80 °C 70 90 204 toff() Overcurrent Reset Delay lack of feedback: I(RM) = 0 to I(LDK) = It(LDK); I(LDK) = 20 mA, CI = 47 nF I(LDK) = 20 mA, CI = 100 nF I(LDK) = 60 mA, CI = 47 nF I(LDK) = 60 mA, CI = 100 nF 205 Vf() Diode Forward Voltage LDK-LDA I(LDK) < 70 mA 206 Rvcc() Transient Protection Resistor VCC vs. LDA 130 1.1 V 4 Ω iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 5/8 ELECTRICAL CHARACTERISTICS Operating Conditions: VCC = 2.4...6 V, RM = 200 Ω...50 kΩ, Tj = -40...125 °C unless otherwise noted Item No. 207 Symbol Vt(MDA) Parameter Shutdown Threshold at MDA Conditions iC-WK only Tj °C Fig. Unit Min. Typ. Max. 0.56 2 V Control Release Flip-Flop 401 VCCen Set Threshold for Enable Flip-Flop 0.6 1.9 V 402 Toff Overtemperature Shutdown 125 150 °C iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 6/8 SAFETY INSTRUCTIONS Laser light can damage the human eye and the eyes of animals! Do not look at any laser light directly or through any optical lens. When handling a laser diode, do not look directly at the light generated by it. Wear appropriate safety glasses to prevent light from entering the eye even by reflection. TURN-ON/OFF BEHAVIOUR Turn-on behaviour After switching on the supply voltage the output stage remains disabled until the internal enabling flip-flop is set by a sufficiently high voltage at LDA. 5.0 V V(VCC) 0V 5.0 V V(LDA) out, thus the laser diode forward voltage is the prime factor determining the lowest possible supply voltage. If the voltage drops below this, the output stage is forcibly saturated and the laser current falls. In this instance iC-WK/L simultaneously discharges control capacitor CI so that no excessive laser diode currents occur when the supply voltage rises again. 0V 5.0 V 200 uA V(VCC) −I(MDA) 0V 0 uA 5.0 V 0.6V V(LDA) V(MDA) 0V 0V Phase I 2.0 V Phase II 200 uA Phase III V(CI) 0 uA −I(MDA) 0V 0.6 V 60 mA I(LDK) 0V V(MDA) 0 mA 0s 10 us 20 us 30 us 40 us t 50 us Phase IV 0V Figure 1: Turn-on behaviour A quick soft start occurs during phase I; the control capacitor CI is loaded at an accelerated rate until the output stage supplies current at LDK. An open-circuit voltage at pin MDA is used to verify the external resistance. Phase II, the initialisation process, begins when current starts to flow at LDK. This phase ends when the laser reaches its threshold current and the monitor current produced raises the potential at resistor RM. The transition to CW operation (phase III) is gradual and primarily influenced by the CI and RM components. CI is properly dimensioned when the voltage overshot at MDA is at a minimum. Turn-off behaviour iC-WK/L functions without a fixed undervoltage lock- Phase V 2.0 V V(CI) 60 mA I(LDK) 0 mA 100 us 150 us 200 us 250 us t 300 us Figure 2: Turn-off behaviour Disruptions in operation The power control is shut down with excessive driver temperature or when the laser current reaches the overcurrent shutdown threshold, for example when the feedback is interrupted. If the monitor diode or the preset resistor RM fail, the device is shutdown in less than 250 µs, provided that the supply voltage applied is high enough. When modulating or switching the laser current via pin MDK (see Application Notes), excessive Voltage occurring at pin MDA also causes a shut down (iC-WK only). iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 7/8 APPLICATION NOTES Setting the output power The output power is simply set by RM = V(MDA) / I(MD); with V(MDA) = Item-No. 101 and I(MD) = monitor current at the desired operating point. RM should be combined from fixed resistor (max. output power) and a trimmer (calibration). Further application notes on iC-WK/L and the data sheets of the evaluation modules and the demo board are available as separate documents. 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. iC-WK, iC-WKL 2.4 V CW LASER DIODE DRIVER Rev D1, Page 8/8 ORDERING INFORMATION Type Package Order Designation iC-WK SO8 MSOP8 SO8 MSOP8 iC-WK SO8 iC-WK MSOP8 iC-WKL SO8 iC-WKL MSOP8 iC-WKL WK Module for P-/M-Type Laser WKL Module for P-/M-Type Laser WK Module for N-Type Laser WKL Module for N-Type Laser iC-WK iCSY WK1D iC-WKL iCSY WK1D iC-WK iCSY WK2D iC-WKL iCSY WK2D WK Evaluation Board WKL Evaluation Board iC-WK EVAL WK4D iC-WKL EVAL WK4D For information about prices, terms of delivery, other packaging options etc. please contact: iC-Haus GmbH Am Kuemmerling 18 D-55294 Bodenheim GERMANY Tel.: +49 (61 35) 92 92-0 Fax: +49 (61 35) 92 92-192 Web: http://www.ichaus.com E-Mail: [email protected]