MHz LASER SWITCH Rev E3, Page /9 FEATURES Laser switch for frequencies from CW up to MHz Spike-free switching of the laser current Dual switching inputs with independent current control Operates as a voltage-controlled current source Pulsed operation with up to ma per channel CW operation with up to ma per channel Simple power control at pin Control to the mean of the laser power in conjunction with ic-wk/l (CW laser diode driver) Supplement to ic-wk/l for pulsed operation Thermal shutdown Protective ESD circuitry ic-hkb for driving blue laser diodes Option: extended temperature range APPLICATIONS Data transmission Laser scanning devices Optical storage devices PACKAGES SO8 thermal pad MSOP8 thermal pad BLOCK DIAGRAM A K A ic WK 4 2 8 CA P M/N RM ic HK/B OVERTEMP. SHUTDOWN M A 3 K M2 EN Suitable laser diode configurations: Operation with constant current (uncontrolled): Operation in conjunction with ic WK (power controlled): N M P 2 4 6 RK RK2 Copyright 26 ic-haus http://www.ichaus.com
MHz LASER SWITCH Rev E3, Page 2/9 DESCRIPTION Laser Switch ic-hk/b enables the spike-free switching of laser diodes with well-defined current pulses at frequencies ranging from DC to MHz. of the emitted laser power is constant (APC), providing there is a constant duty cycle and a switching frequency higher than khz. The diode current is determined by the voltage at pin and by the resistors RK and RK2. The two fast switches are controlled independently via CMOS inputs EN and. The laser diode can thus be turned on and off or switched between different current levels defined by the ratio of RK and RK2. +3... V CA ic HK/B 8 M 3 K M2 Each channel can be operated on ma DC and up to ma pulsed current depending on the frequency, duty cycle and heat dissipation. V() EN The integrated thermal shutdown feature prevents damage from excessive temperature. OVERTEMP. SHUTDOWN A ic-hk/b supplements the laser diode driver ic-wk which uses the monitor current of the laser diode to control the laser power. ic-wk therefore controls the voltage at pin in such a way that the mean value 2 4 6 Figure : Operation as a voltage-controlled current source RK RK2 +3... V 6 VCC A CVCC CA C C nf uf 2.2 nf nf TRANSIENT LED PROTECTION K A 3 D + VREF. V K 8 ic HK/B M K M2 R NQ ic WK FEEDBACK MON./ OVER CURRENT OVERTEMP. RM 2 Ω.. kω CM 4 nf.. EN EN A OVERTEMP. SHUTDOWN R D A 2 4 6 V RK.. RK2.. Figure 2: Operation of ic-hk/b in conjunction with CW driver ic-wk (see application information on optional parts/connections)
MHz LASER SWITCH Rev E3, Page 3/9 PACKAGES SO8tp, MSOP8tp to JEDEC PIN CONFIGURATION SO8tp (top view) PIN FUNCTIONS No. Name Function EN A K 2 3 4 Code......yymm HK 8 6 EN Channel Switching Input 2 A Channel Reference Ground 3 K Driver Output ( Cathode) 4 Channel 2 Reference Ground Channel 2 Switching Input 6 Ground + V Supply Voltage 8 Voltage Reference for Current Control PIN CONFIGURATION MSOP8tp (top view) The Thermal Pad is to be connected to a Ground Plane on the PCB. EN A K ic HK Code
MHz LASER SWITCH Rev E3, Page 4/9 ABSOLUTE MAXIMUM RATINGS Beyond these values damage may occur; device operation is not guaranteed. Item Symbol Parameter Conditions Fig. Unit No. Min. Max. G Voltage at -. 6 V G2 I() Current in - ma G3 V() Voltage at -. 6 V G4 I(K) Current in K DC current - 3 ma G I(A) Current in A DC current - ma G6 I() Current in DC current - ma G V() Voltage at EN,, A and -. 6 V G8 V(K) Voltage at K ic-hk -. 6 V ic-hkb -. V G9 Vd() Susceptibility to ESD at all pins MIL-STD-883, Method 3, HBM pf discharged through. kω kv G Tj Operating Junction Temperature -4 C G Ts Storage Temperature Range -4 C THERMAL DATA Operating Conditions: = 3... V Item Symbol Parameter Conditions Fig. Unit No. Min. Typ. Max. T Ta Operating Ambient Temperature Range (extended range on request) T2 Rthja Thermal Resistance Chip/Ambient (SO8) T3 Rthja Thermal Resistance Chip/Ambient (MSOP8) soldered to PCB, no additional cooling areas therm. pad soldered to approx. 2 cm² cooling area soldered to PCB, therm. pad soldered to approx. 2 cm² cooling area -2 8 C K/W 3 K/W 3 6 K/W 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.
MHz LASER SWITCH Rev E3, Page /9 ELECTRICAL CHARACTERISTICS Operating Conditions: = 3... V, Tj = -2...2 C unless otherwise stated Item Symbol Parameter Conditions Tj Fig. Unit No. C Min. Typ. Max. Total Device Permissible Supply Voltage 3.. V 2 I() Supply Current in CW operation 8 µa 3 I() Supply Current in pulsed operation, f(en, ) = MHz ma 4 V(K) Permissible Voltage at K ic-hk. V ic-hkb 2 V Vc()hi Clamp Voltage hi at Vc() = V(), I() = ma, other pins open 6 Vc(EN)hi Clamp Voltage hi at EN, Vc(EN) = V(EN), I(EN) = ma, other pins open Vc()lo Clamp Voltage lo at, K,, EN,, A, 8 Ipd() Pull-Down Current at, EN,.4.2 V.4.2 V I() = - ma, other pins open -.2 -.4 V µa 9 Toff Overtemperature Shutdown 2 C Laser Control K,, EN, Icw(K) Permissible CW Current in K (per channel) 2 Ipk(K) Permissible Pulsed Current in K (per channel) 3 I(K)rk Current in K in reference to resistor RK (per channel) 4 I(K)rk Current in K in reference to resistor RK (per channel) I(K)ci Current in K in reference to the voltage at (per channel) 6 I(K)ci Current in K in reference to the voltage at (per channel) ma f > khz, thi/t < : ma ic-hk: V() =. V, Tj = 2 C, 4 ton = ms; RKx = Ω 8 ma RKx = Ω 64 9 ma RKx = 2 Ω 43 ma RKx = Ω 3 4 3 ma RKx = Ω 2 28 34 ma RKx = Ω 4 2 ma ic-hkb: V() =. V, Tj = 2 C, ton = ms; RKx = Ω 4 8 2 ma RKx = Ω 4 64 9 ma RKx = 2 Ω 3 8 ma RKx = Ω 2 4 ma RKx = Ω 2 28 4 ma RKx = Ω 3.8 3 ma ic-hk: RKx = Ω, Tj = 2 C, 4-8 ton = ms V() =. V 3 4 6 ma V() =. V 8 ma V() = 2 V 9 2 6 ma V() = 3 V 29 34 39 ma V() = 4 V 48 9 ma V() = V 69 83 ma ic-hkb: RKx = Ω, Tj = 2 C, ton = ms V() =. V 28 4 ma V() =. V 4 8 ma V() = 2 V 8 2 68 ma V() = 3 V 2 2 3 ma V() = 4 V 3 4 4 ma V() = V 4 6 ma tk I(K) Temperature Coefficient. %/K 8 Vs(K) Saturation Voltage at K I(K) = 4 ma.2 V I(K) = 6 ma.3 V I(K) = ma, ic-hk. V I(K) = ma, ic-hkb.8 V 9 I(K) Leakage Current in K ENx = lo, V(K) = µa
MHz LASER SWITCH Rev E3, Page 6/9 ELECTRICAL CHARACTERISTICS Operating Conditions: = 3... V, Tj = -2...2 C unless otherwise stated Item Symbol Parameter Conditions Tj Fig. Unit No. C Min. Typ. Max. tr() K Current Rise Time Iop = ma, I(K): % 9%Iop tf() K Current Fall Time Iop(K) = ma, I(K): 9% %Iop 2 tp() Propagation Delay V(ENx) I(K) 3. ns 3. ns ENx hi lo, V(%) I(%) 3 ns 3 Vt(ENx) Input Threshold Voltage 33 6 %VCC 4 V() Permissible Voltage at. V Vt() Threshold Voltage at I(K) < ma.. V 6 CR() Current Matching Channel/Channel2 V() =..., I(K) = 3...3 ma, RK = RK2.9.
MHz LASER SWITCH Rev E3, Page /9 ELECTRICAL CHARACTERISTICS DIAGRAMS I(K) 3 ma RKx= Ω 2 I(K) t r t f 2 RKx= Ω RKx= 2 Ω I op RKx= 3 Ω 9 % I op % I op t RKx= 4 Ω RKx= Ω RKx= 6 Ω RKx= 8 Ω RKx= Ω RKx= Ω RKx= 2 Ω RKx= 3 Ω RKx= Ω.2.4.6.8 2 2.2 2.4 2.6 V V() Figure 3: Laser current pulse in K Figure 4: Diode current vs. V(Cl) at Tj = 2 C I(K) ma 6 4 3 RKx = Ω RKx = Ω RKx = 2Ω RKx = 3Ω RKx = 4Ω RKx = Ω 2 RKx = 6Ω RKx = 8Ω RKx = Ω RKx = Ω RKx = 2Ω RKx = 3Ω RKx = Ω 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8V V() I(K) 2 ma 8 6 4 2 RKx = Ω RKx = Ω RKx = 2Ω RKx = 3Ω RKx = 4Ω RKx = Ω RKx = 6Ω RKx = 8Ω RKx = Ω RKx = Ω RKx = 2Ω RKx = 3Ω RKx = Ω 3. 4 4. V V() Figure : Diode current vs. V(Cl) at Tj = 2 C Figure 6: Diode current vs. V(Cl) at Tj = 2 C I(K) I(K). A 2 ma 2 max RKx = Ω max RKx = Ω. min min.. 2 V() 2 3 4 V V() Figure : Diode current variation vs. V() at V(K) = 3 V Figure 8: Diode current variation vs. V() at V(K) = 3 V
MHz LASER SWITCH Rev E3, Page 8/9 DESCRIPTION OF FUNCTIONS Laser current dependency of V(Cl), RK, RK2 Depending on the laser diode different diode currents are necessary to obtain the required laser power. The values for V(), RK and RK2 can be determined for the required diode current at room temperature from the opposite diagram. A parallel to the x axis must be drawn through the desired diode current. Either RKx can be obtained for a required value of V() or the respective value of V(VI) can be achieved for a given RKx. Thermal Shutdown ic-hk/b is protected by an integrated thermal shutdown feature. When the shutdown temperature is reached both channels are locked. I(K) 3 ma 2 2 RKx= Ω 2 RKx= Ω RKx= 2 Ω RKx= 3 Ω RKx= 4 Ω RKx= Ω RKx= 6 Ω RKx= 8 Ω RKx= Ω RKx= Ω RKx= 2 Ω RKx= 3 Ω RKx= Ω.2.4.6 3.8 2 2.2 2.4 2.6 V. Figure 9: Diode current vs. V(Cl) at Tj = 2 C V() APPLICATION NOTES Application notes for ic-hk are available as a separate document. 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.
MHz LASER SWITCH Rev E3, Page 9/9 ORDERING INFORMATION Type Package Order Designation ic-hk SO8tp ic-hk SO8 MSOP8tp ic-hk MSOP8 ic-hkb SO8tp ic-hkb SO8 MSOP8tp ic-hkb MSOP8 For information about prices, terms of delivery, other packaging options etc. please contact: ic-haus GmbH Tel.: +49 (6 3) 92 92- Am Kuemmerling 8 Fax: +49 (6 3) 92 92-92 D-294 Bodenheim Web: http://www.ichaus.com GERMANY E-Mail: sales@ichaus.com