Operating Sanyo laser diodes with integrated drivers iC-Haus GmbH Uwe Malzahn November 24, 2006 Abstract The following describes application circuitry built with laser diode drivers by iC-Haus to operate the most commonly used Sanyo laser diodes in both CW and pulse mode. Sanyo is a trademark of Sanyo Electric Co., Ltd. APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 2/16 CONTENT GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 CW OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 DL-3147-260 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 DL-4148-021, DL-4148-031 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 DL-3149-057 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 DL-3146-151, DL-3146-152 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Analogue modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 PULSE OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DL-3147-260 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DL-4148-021, DL-4148-031 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DL-3149-057 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 DL-3146-151, DL-3146-152 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 3/16 GENERAL INFORMATION The advantages of integrated driver components as opposed to discrete circuitry are obvious. Compared to the typical suggestions for circuits integrated solutions only require about one quarter of the components, thus requiring less space, and are significantly more reliable. Integrated drivers usually also have a considerably higher degree of accuracy. Most discrete solutions have just one specific basic function. Temperature-stable voltage references (band-gap references), for example, cannot be implemented discretely; ICs must be used for this purpose anyway. Monitor current 1 mA 100 uA 10 uA 111 000 000 111 000 111 000 111 000 111 000 111 000 111 000 111 000 111 iC−WJB 000 111 00 11 000 111 00 11 000 111 00 11 000 111 000 111 000 111 000 111 000 111 000 111 000 111 000 111 000 111 000 111 000 111 00 11 000 111 00 11 000 00 iC−WK 111 11 000 111 000 111 000 iC−WKL 111 000 111 000 111 0000 1111 000 111 0000 1111 111111 000000 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 000000 111111 0000000 1111111 0 1 000000 111111 0000000 1111111 0 1 iC−WJZ iC−WJ iC−WKM iC−WKN iC−WKP In selecting suitable driver modules for a laser diode the following criteria must be taken into consideration: Laser current 100 mA • • • • • • • Is a monitor diode present? Pin configuration (N, M or P type∗ ) Maximum laser diode current Monitor current range CW or pulse operation Pulse frequency (range) Fixed or variable duty cycle Laser diode drivers from iC-Haus have been designed for operation with monitor diodes (regulation of the optical output power = APC or automatic power control). With the exception of iC-HK, an integrated monitor diode is thus imperative. Not every device supports all three pin configurations. The maximum laser diode current determines the necessary driving capability which each individual device should have. The monitor current within the required setup range must also be able to be processed by the selected driver device. Exceeding this permissible monitor current range damages neither the laser diode nor the device; the control accuracy will, however, decrease and the susceptibility to interference rise. Figure 1 shows the monitor and laser current range covered in CW operation. ∗ Also often referred to as types I, II and III. 200 mA 300 mA 350 mA Figure 1: Monitor / laser current range in CW operation The operating mode (CW or pulse), pulse frequency (fixed or variable) and duty cycle (fixed or variable) determine whether a simple averaging control is sufficient or whether each individual pulse has to be controlled separately. Figure 2 describes the frequency and laser current range covered by iC-Haus laser diode drivers. Laser diode current 300 mA 200 mA 100 mA 111 000 101011111111 00000000 000 111 00000000 11111111 000 111 00000000 000101011111111 111 00000000 101011111111 00000000 11111111 1011111111111111111111111111111111111111111111111 00000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000 11111111111111111111111111111111111111111111111 10111 000 01111 100000000000000000000000000000000000000000000000 11111111111111111111111111111111111111111111111 00000000000000000000000000000000000000000000000 000 10111 000 iC−HK 00000000 000 111 iC−HKB 1010101011111111 00000000 000 111 1011111111 00000000 11111111 000 111 iC−NZ 101011111111 00000000 000 111 00000000 000 111 iC−WJ 101011111111 00000000 11111111 000 111 iC−WKM 00000000 000 iC−WJZ 111 101011111111 00000000 11111111 000 111 iC−WKN 00000000 11111111 000 111 iC−VJ 101011111111 00000000 000 111 iC−WKP iC−VJZ 111 00000000 11111111 000 101011111111 00000000 000 111 00000000 11111111 000 111 0 1 00000000 11111111 101011111111 00000000 000 111 0000 1111 0 1 00000000 11111111 00000000 11111111 000 111 00 11 0000 1111 0 1 00000000 11111111 101011111111 00000000 000 111 00 11 0000 1111 0 1 00000000 11111111 000 111 00 11 0000 1111 1011111111 00000000 11111111 000 111 0000 1111 iC−WK 0 1 00000000 000 iC−WJB 111 0000 1111 0 1 00000000 11111111 000 111 iC−WKL 0000 1111 101011111111 00000000 000 111 00000000 11111111 000 111 101011111111 00000000 000 111 000 111 00000000 11111111 000 111 000000000 000 111 000 111 10111111111 00000000 11111111 000 111 01111 Frequency 000000000 000 000 111 10111111111 1 0 0101 000 111 CW 1 kHz 10 kHz 100 kHz 1 MHz 10 MHz 100 MHz Figure 2: Frequency / current range The following examples are geared towards some of the most commonly used Sanyo laser diodes. APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 4/16 CW OPERATION In plain CW operation an averaging control unit is totally sufficient. Stability is provided when the optical output signal does not exhibit any notable overshoot for the set operating point when switched on. imum of 45 mA at a maximum output power of 7 mW. Here, either the Universal Laser Saver iC-WK/L can be used (Figure 3) or, if the laser diode casing is to be connected to ground for improved thermal dissipation or easier assembly in a module, iC-WKP (Figure 4). DL-3147-260 The DL-3147-260 is a P-type laser diode with a max- Figure 3: iC-WK/L with a DL-3147-260 Dimensioning information for iC-WK/L CI: integration capacitor; value must be determined empirically; size is sufficient if the optical output does not exhibit any overshoot when switched on CL: back-up capacitor, absolute value not critical; can be increased for greater stability CP: optional; only necessary with longer connections between the driver output and laser diode CV: blocking capacitor, absolute value not critical RM: power setting: RM = 0.5 V / Im, with Im = monitor current of the laser diode with the required output power. Resistance RM, used to set the operating point, is always calculated according to the same principle, as given in the following formulae: RMmin = V (MDA) Pnom ∗ Imnommax Pset (1) RMmax = V (MDA) Pnom ∗ Imnommin Pset (2) where Imnommin and Imnommax represent the monitor current range at nominal output power Pnom , as given in the laser diode data sheet, and Pset is the laser power to be set. APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 5/16 At 3 mW output power and using the information given in the DL-3147-260 and iC-WK/L data sheets this amounts to: RMmin = RMmax = 0.5 V 5 mW ∗ = 2083.33 Ω 0.4 mA 3 mW 0.5 V 5 mW ∗ = 10416.67 Ω 0.08 mA 3 mW If the output power is to be set within a range of 3 to 5 mW, for example, the following applies: RMmin = RMmax = 0.5 V 5 mW ∗ = 1250 Ω 0.4 mA 5 mW 0.5 V 5 mW ∗ = 10416.67 Ω 0.08 mA 3 mW It is prudent here to divide resistor RM into a fixed resistor (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ) for the setup process: RMmin ≥ RMfix = 1.2 kΩ RMmin ≥ RMfix = 2 k Ω RMmax − RMfix ≤ RMvar = 10 k Ω RMmax − RMfix ≤ RMvar = 10 k Ω Figure 4: iC-WKP with a DL-3147-260 Dimensioning information for iC-WKP CI: integration capacitor; value must be determined empirically; size is sufficient if the optical output does not exhibit any overshoot when switched on CVCC: blocking capacitor, absolute value not critical RL: reduces the power dissipation in the IC and improves the stability of the control unit; absolute value not critical provided LDA does not saturate CLDA: back-up capacitor, absolute value not critical; can be increased for greater stability CM: optional; reduces susceptibility of spike detection at pin MDK RM: power setting: RM = 1.24 V / Im, with Im = monitor current of the laser diode with the required output power. preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 6/16 Using the information given in the DL-3147-260 data sheet RM is calculated as shown in Equations 1 and 2. If the output power is to be set within a range of 3 to 5 mW, for example, the following applies: At 3 mW this amounts to: RMmin = 1.24 V 5 mW ∗ = 5166.67 Ω RMmin = 0.4 mA 3 mW RMmax = 5 mW 1.24 V ∗ = 25833.33 Ω 0.08 mA 3 mW RMmax = 1.24 V 5 mW ∗ = 3100 Ω 0.4 mA 5 mW 1.24 V 5 mW ∗ = 25833.33 Ω 0.08 mA 3 mW Division of resistor RM into a fixed resistor (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ): RMmin ≥ RMfix = 3 k Ω RMmin ≥ RMfix = 5.1 kΩ RMmax − RMfix ≤ RMvar = 22 k Ω RMmax − RMfix ≤ RMvar = 22 k Ω DL-4148-021, DL-4148-031 DL-4148-021 and DL-4148-031 are N-type laser diodes with a maximum of 80 mA at a maximum output power of 12 and 10 mW respectively. Here, either iC-WJ (Figure 5) or iC-WKN can be used. If the laser diode casing is to be connected to ground for improved thermal dissipation or easier assembly in a module, in both cases the voltage must be supplied from -5 V (Figure 6). C1 10 uF 1 GND KLD 8 C3 5 nF R1 12 Ω LD AMD 2 7 CWD CI 100 nF RSET 10 kΩ WDOG 3 CI IN 6 REF 4 ISET VCC iC−WJ 5 +5 V C2 100 nF Figure 5: DL-4148-021 or DL-4148-031 with iC-WJ MD preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 7/16 Dimensioning information for iC-WJ C1, C2: blocking capacitors, absolute value not critical C3: optional; only necessary with longer connections between the driver output and laser diode CI: integration capacitor; value must be determined empirically; size is sufficient if the optical output does not exhibit any overshoot when switched on RSETmax = 10 mW 1.22 V ∗ = 30500 Ω 0.05 mA 8 mW Division of resistor RSET into a fixed resistance (RSETmin ≥ RSETfix = b Poutmax ) and a trimmer (RSETvar ): RSETmin ≥ RSETfix = 3.6 k Ω R1: reduces the power dissipation in the IC; output KLD must not saturate! RSET: power setting: RM = 1.22 V / Im, with Im = monitor current of the laser diode with the required output power. Using the information given in the DL-4148-021 and DL-4148-031 data sheets the following formulae are calculated for RM in keeping with Equations 1 and 2: RMmin = V (ISET ) Pnom ∗ Imnommax Pset RSETmax − RSETfix ≤ RSETvar = 33 k Ω If the output power is to be set within a range of 5 to 10 mW, for example, the following ratios apply: RSETmin = (3) RSETmax = RMmax = V (ISET ) Pnom ∗ Imnommin Pset At 8 mW this amounts to: RSETmin = 1.22 V 10 mW ∗ = 3812.5 Ω 0.4 mA 8 mW 1.22 V 10 mW ∗ = 3050 Ω 0.4 mA 10 mW 1.22 V 10 mW ∗ = 48800 Ω 0.05 mA 5 mW (4) RSETmin ≥ RSETfix = 3 k Ω RSETmax − RSETfix ≤ RSETvar = 47 k Ω APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 8/16 6 VCC LDA 7 CVCC CLDA ..47 nF.. ..1 uF.. TRANSIENT PROTECTION MDK 4 MDA 5 MD − iC−WKN 1 LD + VREF 0.5 V CI 2 D LDK 8 NQ R CI RM 0.08..200 k Ω OVERCURRENT OVERTEMP. −5 V 1 ..100 nF.. CM 47 pF FEEDBACK MON. GND AGND 3 ca. 3 Ohm Figure 6: DL-4148-021 or DL-4148-031 with iC-WKN Dimensioning information for iC-WKN CI: integration capacitor; value must be determined empirically; size is sufficient if the optical output does not exhibit any overshoot when switched on Division of resistor RM into a fixed resistance (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ): RMmin ≥ RMfix = 1.5 kΩ CLDA: back-up capacitor, absolute value not critical; can be increased for greater stability CM: optional; reduces susceptibility of spike recognition at pin MDA RMmax − RMfix ≤ RMvar = 15 k Ω CVCC: blocking capacitor, absolute value not critical If the output power is to be set within a range of 5 to 10 mW, for example, the following ratios apply: RM: power setting: RM = 0.5 V / Im, with Im = monitor current of the laser diode with the required output power. RMmin = Using the information given in the DL-4148-021 and DL-4148-031 data sheets RM is calculated as shown in Equations 1 and 2. RMmax = At 8 mW this amounts to: 0.5 V 10 mW ∗ = 1250 Ω 0.4 mA 10 mW 0.5 V 10 mW ∗ = 20000 Ω 0.05 mA 5 mW RMmin = 0.5 V 10 mW ∗ = 1562.5 Ω 0.4 mA 8 mW RMmin ≥ RMfix = 1.2 k Ω RMmax = 0.5 V 10 mW ∗ = 12500 Ω 0.05 mA 8 mW RMmax − RMfix ≤ RMvar = 20 k Ω APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 9/16 DL-3149-057 The DL-3149-057 is an N-type laser diode with a maximum of 45 mA at a maximum output power of 7 mW. Here, universal Laser Saver iC-WK/L can be used. If +2.4..+6 V 6 the laser diode casing is to be connected to ground, the voltage can also be supplied from -5 V as with iCWKN (see Figure 6). VCC LDA 7 CVCC CLDA ..47 nF.. ..1 uF.. TRANSIENT PROTECTION MDK 4 MDA 5 MD − iC−WKL 1 LD + VREF 0.5 V CI 2 D LDK 8 NQ R CI RM 200..50 k Ω OVERCURRENT/ OVERTEMP. 1 iC−WK FEEDBACK MON. ..100 nF.. GND AGND CM 47 pF 3 GND Figure 7: DL-3149-057 with iC-WK/L Dimensioning information for iC-WK/L Using the information given in the DL-3149-057 data sheet RM is calculated as shown in Equations 1 and 2. If the output power is to be set within a range of 3 to 5 mW, for example, the following ratios apply: At 3 mW this amounts to: RMmin = RMmin = RMmax = 0.5 V 5 mW ∗ = 250 Ω 2 mA 5 mW 0.5 V 5 mW ∗ = 416.67 Ω 2 mA 3 mW 0.5 V 5 mW ∗ = 1666.67 Ω 0.5 mA 3 mW It is prudent here to divide resistor RM into a fixed resistor (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ): RMmax = 0.5 V 5 mW ∗ = 1666.67 Ω 0.5 mA 3 mW RMmin ≥ RMfix = 240 Ω RMmin ≥ RMfix = 390 Ω RMmax − RMfix ≤ RMvar = 1.5 k Ω RMmax − RMfix ≤ RMvar = 1.5 k Ω APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 10/16 DL-3146-151, DL-3146-152 DL-3146-151 and DL-3146-152 are 405 nm M-type laser diodes with a maximum of 70 mA and 110 mA at a maximum output power of 7 and 35 mW respectively. The higher forward voltage (ca. 5.5 V) and the neces- sary connection of the laser diode casing to ground for improved thermal dissipation mean that only iC-WKM can be used here (Figure 8). This device also permits the operation of an M-type laser diode (whose casing is connected to ground) from a single supply. Figure 8: DL-3146-151 or DL-3146-152 with iC-WKM Dimensioning information for iC-WKM CI: integration capacitor; value must be calculated empirically; size is sufficient if the optical output does not exhibit any overshoot when switched on; larger values are necessary if CM is used CM: optional; reduces sensitivity of spike recognition at pin MDA RMmax = 5 mW 0.25 V ∗ = 8333.33 Ω 0.05 mA 3 mW As the data sheet only gives the typical value for the monitor current and no maximum value the division of resistor RM into a fixed resistor (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ) could be as follows: CVCC: blocking capacitor, absolute value not critical CVCCA: back-up capacitor, absolute value not critical; can be increased for greater stability RM: power setting: RM = 0.25 V / Im, with Im = monitor current of the laser diode with the required output power. RMtyp ≥ RMfix = 390Ω RMmax − RMfix ≤ RMvar = 10 k Ω If the output power is to be set within a range of 3 to 5 mW, for example, the following ratios apply: Using the information given in the DL-3146-151 data sheet RM is calculated as shown in Equations 1 and 2. RMtyp = At 3 mW this amounts to: RMtyp = 0.25 V 5 mW ∗ = 2083.33 Ω 0.2 mA 3 mW RMmax = 0.25 V 5 mW ∗ = 1250 Ω 0.2 mA 5 mW 0.25 V 5 mW ∗ = 8333.33 Ω 0.05 mA 3 mW APPLICATION NOTES preliminary Operating Sanyo laser diodes with integrated drivers Rev A1, Page 11/16 RMtyp ≥ RMfix = 240 Ω RMmax − RMfix ≤ RMvar = 10 k Ω RMmax − RMfix ≤ RMvar = 3.3 k Ω If the output power is to be set within a range of 5 to 35 mW, for example, the following ratios apply: RM can be calculated using the information given in the DL-3146-152 data sheet. At 25 mW this amounts to: RMmin = RMmin = 0.25 V 35 mW ∗ = 350 Ω 1 mA 25 mW RMmax = RMmax = 0.25 V 35 mW ∗ = 250 Ω 1 mA 35 mW 0.25 V 35 mW ∗ = 17500 Ω 0.1 mA 5 mW 0.25 V 35 mW ∗ = 3500 Ω 0.1 mA 25 mW Division of resistor RM into a fixed resistance (RMmin ≥ RMfix = b Poutmax ) and a trimmer (RMvar ): RMmin ≥ RMfix = 330Ω RMmin ≥ RMfix = 240 Ω RMmax − RMfix ≤ RMvar = 22 k Ω preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 12/16 Analogue modulation With regard to all of the driver devices described herein, in principle analog modulation (modulation depth 100%) is possible up to a specific cutoff frequency which is determined by the integration capacitor (CI). This can either be achieved through direct modulation at the operating point adjusting resistor (see Figures 9 and 10) or, with devices in the iCWK product range, at the second monitor current input (Figure 11). Taking the operating point set using RSET (cf. Equations 3 and 4), the output power is calculated thus: POUT POUT = = Pnom + Pmod Pnom + Pnom ∗ (5) V (ISET )−VMOD R2 V (ISET ) RSET (6) Parallel to this the output power for iC-WK is calculated as shown in Figure 10. +5 V C1 100 uF C3 2 nF 1 GND LD KLD 8 MD R1 12Ω AMD 2 CI 22 nF VMOD 0..1.5 V R2 10 kΩ WDOG 3 7 CWD CI IN 6 +5 V REF 4 ISET iC−WJ/WJZ RSET 10 kΩ VCC 5 C2 100 nF Figure 9: Analogue modulation in the iC-WJ product range preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 13/16 +VB C2 100nF 1 GND LDK 8 LDA 7 J I 2 CI C3 100nF C1 1µF + 3 − AGND C4 2.2nF 6 VCC 0.5V 4 MDA MDK iC−WK 5 R1 200Ω...50kΩ Figure 10: Analogue modulation in the iC-WK product range +VB C2 100nF GND 1 GND LDK 8 LDA 7 iC−WK/L J I 2 CI C1 C3 100nF 1µF + 3 − AGND 0.5V Rmod D/A 4 MDK C4 2.2nF 6 VCC MDA 5 R1 200Ω...50kΩ Figure 11: Analogue modulation in the iC-WK product range using the second monitor input Pin MDK is a current input. A controlled current sink is thus ideal for modulation. If modulation occurs from a voltage source (such as a D/A converter, for example), the current- and temperature-dependent voltage at pin MDK must be taken into consideration when calculat- ing the percentage of modulation according to Equation 5. POUT = Pnom + Pnom ∗ VMOD−V (MDK ) Rmod V (MDA) R1 preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 14/16 PULSE OPERATION In pulse operation a distinction must be made between devices with an averaging control unit, where only the average optical output power is kept constant (iC-VJ and iC-WJ products), and those with a peak optical power control unit (iC-NZ), where each individual pulse is controlled (with limitations). As a matter of principle the averaging control unit requires a fixed duty cycle. In addition the regulating constant must be adjusted so that it tarries with the lowest occurring pulse frequency which in general constitutes a useful low pulse frequency of several 10 kHz. For frequencies below this the integration capacitor would have to be disproportionately large which also considerably increases the start-up time. However, CW-like operation can be more or less achieved with the aid of a watchdog (iC-WJ products) at low pulse frequencies. Here, peak optical power control is substantially more flexible, permitting variable pulse widths and pulse frequencies within broad margins. At low frequencies or with long pulse intervals, however, pulse delays can be caused by settling processes. DL-3147-260 The DL-3147-260 is a P-type laser diode with a maximum of 45 mA; only iC-NZ can thus be used here for pulse operation. The circuitry illustrated in Figure 12 enables pulse operation of a P-type laser diode with up to 320 mA and up to three separately regulated output levels. REGEN SDIS VDD In this instance a certain pulse delay must be reckoned with. LENL LENM LENH VDD LDA RVDD C1 Current Monitor RSI Laser Driver RSI RSIOV LDAOK NSEN RMH CLDA RML RMM NTREN EN MDOK ENCAL CIOK Finite State Machine RMDH LDKGND NERR RMDM NSEN MDL NSF NPDR TEMPOK LD Safety Monitor Diode VBG and Reference SMD + MD LDKH VBG and Reference LDKM LDKL SMD(1) − CIH VSH + CIH CIM SMD(0) − CIL CIM VSL CIL VREF Figure 12: DL-3147-260 in pulse operation with iC-NZ A detailed description of the setup procedure can be found in the iC-NZ data sheet which also goes into detail about the optional single-failure-proof feature of the device. DL-4148-021, DL-4148-031 DL-4148-021 and DL-4148-031 are N-type laser diodes with a maximum of 80 mA. Depending on the pulse frequency and duty cycle required, here either iC-WJ (Figure 13) or iC-NZ (Figure 14) can be used. In applications with a fixed pulse frequency, such as light barriers, for example, iC-VJ is also a possible option (Figure 15). Detailed instructions for dimensioning can be found in the relevant data sheets. preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 15/16 5 +5V VCC DRIVER 3 REF C1 100uF 1 REFERENCE 4 C3 2nF THERMAL SHUTDOWN ISET 8 LD MD KLD RSET 10k Ω R1 12Ω 6 VCC INPUT IN POWER DOWN REF 7 AMD 74HCxx 2 4 WATCHDOG iC−WJ CWD GND CI 2 1 3 CWD CI 100..470nF Figure 13: DL-4148-021 or DL-4148-031 in pulse operation with iC-WJ REGEN SDIS VDD LENL LENM LENH VDD C1 LDA Current Monitor RSI Laser Driver RSI RSIOV LDAOK NSEN CLDA EN LD MD NTREN LDKH MDOK LDKM CIOK LDKGND Finite State Machine ENCAL NERR LDKL NSEN CIH NSF CIH CIM NPDR TEMPOK CIM CIL CIL MDL Safety Monitor Diode VBG and Reference SMD + RMDH VBG and Reference RMDM SMD(1) − VSH + RMH SMD(0) RGND − VSL VREF Figure 14: DL-4148-021 or DL-4148-031 in pulse operation with iC-NZ RMM RML preliminary APPLICATION NOTES Operating Sanyo laser diodes with integrated drivers Rev A1, Page 16/16 Sync DC Monitor 5V R3 10kΩ 13 4 MO MI C3 100nF 12 C4 100uF VCC DRIVER OUTPUT DIVIDER 16:1 Q 14 1 PRF NQ NQ 15 AMD 1 KLD 2 GND 3 MD LD MONITOR NPRF 7 4 2 POWER ON THERM. SHUTDOWN REFERENCE OSCILLATOR 3 5 R RC 5 6 6 iC−VJ ISET CI 9 11 R1 800 Ω AGND 7 C2 100..470nF RSET 10kΩ C1 100pF Figure 15: DL-4148-021 or DL-4148-031 in pulse operation with iC-VJ DL-3149-057 The DL-3149-057 is an N-type laser diode with a maximum of 45 mA. Here the same applies as for DL-4148021 and DL-4148-031. DL-3146-151, DL-3146-152 DL-3146-151 and DL-3146-152 are 405 nm M-type laser diodes with a maximum of 70 mA and 110 mA respectively. The considerably higher forward voltage of ca. 5.5 V means that only iC-NZ can be used here (Figure 16). The laser diode is then powered separately from a higher voltage. 5..12 V REGEN SDIS LENL LENM LENH VDD VDD C1 LDA Current Monitor RSI Laser Driver LD RSI RSIOV LDAOK NSEN CLDA NTREN MD LDKH MDOK EN LDKM CIOK LDKGND Finite State Machine ENCAL NERR LDKL NSEN CIH NSF CIH CIM NPDR TEMPOK CIM CIL MDL CIL Safety Monitor Diode VBG and Reference SMD + RMDM VBG and Reference RMDH SMD(1) − VSH + RMH SMD(0) RMM RML RGND − VSL VREF Figure 16: DL-3146-151 and DL-3146-152 in pulse operation with iC-NZ NO WARRANTY THIS INFORMATION IS DISTRIBUTED IN THE HOPE THAT IT WILL BE USEFUL, BUT WITHOUT ANY WARRANTY. IT IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THIS INFORMATION IS WITH YOU. SHOULD THIS INFORMATION PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. IN NO EVENT THE AUTHOR WILL BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THIS INFORMATION, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.