LPD70 Series 250mA, 28Vdc Optically Isolated Dual Relay Part Number Description LPD70 250mA, 28Vdc dual solid-state relay MECHANICAL SPECIFICATION FEATURES/BENEFITS • Current limiting output • Thermal protection • Automatic recovery • Overload protection • Dual output: Two relays in one package • Low voltage drop MAXIMUM Figure 1 – LPD70 relay; dimensions in inches (mm) Tolerances are +/- .005 inch (.127) unless otherwise specified INPUT (CONTROL) SPECIFICATIONS (–40 to 85°C) Min Max Units Control Voltage Range (See Note 1) 4.0 7.0 Vdc Input Current @ 5 Vdc (See Fig 2)12 mA Must Turn-On Voltage Vdc 4 Must Turn-Off Voltage 0.8 Vdc Must Turn-Off Current 50 µA Reverse Voltage –7 DESCRIPTION The LPD70 is a dual-output 28Vdc plastic relay with internal thermal protection. The relay utilizes optical isolation to provide excellent input-to-output isolation. The LPD70 offers a current limiting output to protect itself and associated load circuits from transient current overloads. During an overcurrent condition, the LPD70 clamps the current to a safe operating value. The LPD70 also offers thermal protection. The thermal protection is activated by junction temperature. In case of an overload or shorted load condition, the thermal protection limits the junction temperature. The LPD70 returns to normal operation automatically once the overload is removed. Vdc )NPUT#URRENTM! )NPUT6OLTAGE6DC INPUT CURRENT VS. INPUT VOLTAGE Figure 2 © 2007 TELEDYNE RELAYS (800) 284-7007 • www.teledynerelays.com Page 2DSLPD70 Rev. B LPD70 Series 250mA, 28Vdc Optically Isolated Dual Relay OUTPUT (LOAD) SPECIFICATIONS Min Max Units Load Voltage Rating 33 Vdc Load Current (See Fig 6) 0.25 A Transient Voltage 80 Vdc Transient Supply Voltage with Load shorted (5 sec max) 46 Vdc Output Capacitance @ 25Vdc 200 pF On-State Voltage Drop (See Fig 4) 0.5 Vdc On Resistance 2.0 Ohm Off-State Leakage Current (33Vdc)10 µA Turn-On Time 2.5 ms Turn-Off Time1 ms Overload Current Limit (See Fig 5) 0.9 2%,!9! ). /54 n 0). 2%,!9" n ). /54 n n 6DC 6 A ,OAD ! 6SUPPLY 6DC 4YPICAL ,OAD " 6 OVERLOAD/THERMAL PROTECTION SPECIFICATIONS (NOTE 8) TYPICAL WIRING DIAGRAM Figure 3 Min Typical Max Units °C Activation Time (See Fig. 7, Note7) 70 mArms ms ,OAD#URRENT! ENVIRONMENTAL SPECIFICATIONS Min Max Units Operating Temperature –40 +85 °C Storage Temperature –55 +100 °C Junction Temperature 100 °C °C/W Shock1500 g Vibration100 g 500 Vac Insulation Resistance (@500 Vdc)109 Ohm Resistance to Soldering Heat 5 MIL STD 202, method 208 Thermal Shock MIL STD 202, method 107 HAST JEDEC Test Method A110 130°C 85% RH, no power applied, 50 hours /UTPUT6OLTAGE$ROP6 LOAD CURRENT VS. OUTPUT VOLTAGE DROP OVER TEMPERATURE Figure 4 pF Solder Dip, 10 seconds at +260°C MIL STD 202, method 210 Solderability /VERLOAD#URRENT,IMIT! Isolation Thermal Resistance (Junction to Ambient) each relay120 Dielectric Strength o# 6 0 Output Current (after 120 sec) Vdc o# 33 Junction Activation150 Temperature o# Output Load Voltage n n n n n !MBIENT4EMPERATURE # TYPICAL OVERLOAD CURRENT VS. TEMPERATURE Figure 5 Page Specifications UNDER REVISION CONTROL © 2007 TELEDYNE RELAYS 2DSLPD70 Rev. B LPD70 Series 250mA, 28Vdc Optically Isolated Dual Relay THEORY OF OPERATION LPD70 relays operate with 0.25 amp loads from –40° to +85°C. Overloads are current-limited to about 0.6 amps. A temperature sense circuit in intimate contact with the output power switch opens the switch at elevated junction temperatures. This thermal shutdown results in a periodic cycling of the output switch, with the overload current decaying over time. Once the overload is removed, the relay returns to normal operation. The LPD70 relay survives overloads, including shorted loads, at load voltages up to 33Vdc. ,OAD#URRENT! n n !MBIENT4EMPERATURE # LOAD CURRENT VS. AMBIENT TEMPERATURE Figure 6 /UTPUT#URRENTWITH,OAD3HORTED !MPS SECONDS Activation Time -ILLISECONDS TYPICAL OVERLOAD CURRENT VS. TIME Figure 7 ). ).054WITH ,%$ n). /PTICAL )SOLATION $ETECTION #IRCUIT NOTES 1.For input voltages greater than 7 volts, use an external resistor in series with the relay input. Rext. = (Vin–7 Vdc)/0.012 Amps 2.Relay input voltage transitions should be less than 1.0 millisecond. 3.Above approximately 0.6 Amps load (overload), the relay becomes current limited. In this mode of operation, the voltage across the relay contacts is: Vcontact ≅ Vsupply – [(0.6 Amp) (Rload)] The relay will limit current in an overload condition until the overload is removed. 4.Maximum load current ratings are with the relay in free air and soldered to a printed circuit board. 5.Loads may be attached to either the positive or negative output terminal. 6.Timing is measured from the input voltage transition to the 10% or 90% points on the output voltage transition. 7.Activation time is the time for the thermal protection circuit to take effect. 8.The LPD70 relay withstands shorted Loads at 33 Vdc Max supply voltage indefinitely, and survives shorted load conditions at 46 Vdc Max Supply Voltage for 5 seconds Max. 4URN/FF 4IMING #IRCUIT /UTPUT3WITCH -/3&%4 WITH#URRENT ,IMIT /54 n/54 4EMPERATURE 3ENSE FUNCTIONAL BLOCK DIAGRAM Figure 8 © 2007 TELEDYNE RELAYS (800) 284-7007 • www.teledynerelays.com Page 2DSLPD70 Rev. B