MDT75C271 OTP Encoder 1. General Description The MDT75C271 i s an OTP Encoder using CMOS technology. It has a maximum of 20 bits addressing code providing up to one million codes. It can reduce any code collision and unauthorized code scanning possibilities. 2. Features l CMOS technology. l Low standby current : 1.0 uA. l Wide range of Operating Voltage : Vdd = 4.5V ~ 12V. l Up to 4 data pins. l Total 1048576 address codes. l Built-in RC oscillator with single external resistor. l Available in DIP and SOP package. l Automatically enter sleep mode if press button over 6 ~ 10 sec 3. Pin Assignment MDT75C271P / 75C271S 8 pin DIP / SOP OSCR Vdd Vss TXD 1 2 3 4 8 7 6 5 K3 K2 K1 K0 4. Pin Function Description Symbol I/O OSCR I Function Description Connect a resistor to Vdd to adjust internal RC freq. Vdd Positive power supply 4.5V ~ 12 V. Vss Ground. TXD O Data output pin. K0 I Data input with pull low Resistor. K1 I Data input with pull low Resistor. K2 I Data input with pull low Resistor. K3 I Data input with pull low Resistor. This specification is subject to be changed without notice. Please visit our web site for the most updated information. 1 of 5 2005/1/6 Ver. 1.2 MDT75C271 OTP Encoder 5.Output Data Reporting Output data frame Preamble C0 ~ C19 ( 1048576 address codes ) D0 D1 D2 D3 Preamble : 4 Ick 124 Ick for 75C271 Data High : 12 Ick 4 Ick Data Low : 4 Ick 12 Ick Note : 1 Ick = 8 OSC clocks 6. Key 0 ~ 3 combination table K3 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 K2 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 K1 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 K0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 D3 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 D2 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 D1 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 D0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 This specification is subject to be changed without notice. Please visit our web site for the most updated information. 2 of 5 2005/1/6 Ver. 1.2 MDT75C271 OTP Encoder 7. Absolute Maximum Rating Symbol Parameter Vdd Conditions Rating Unit Supply Voltage -0.3 ~ 13 V Vi Input Voltage -0.3 ~ Vdd+0.3 V Vo Output Voltage -0.3 ~ Vdd+0.3 V Tst Storage Temp. -40 ~ 125 Top Operating Temp. -20 ~ 70 Pdis Max. Power dissipation Vdd = 12V 300 mV 8. DC Electrical Characteristics (TA=0℃ to 70℃) Symbol Parameters Vdd Operating Voltage Isb Stand by current Conditions Min. Typ. Max. Unit 4.5 5 12 V 1.0 3.0 uA 0.5 1.0 mA Vdd = 12V, OSC stop K0 ~ K3 = Low Output Unloaded Iop Operating current Ioh Source current Vdd =12V, Voh = 6V 4.5 mA Iol Sink Current Vdd =12V, Vol = 6V 4.5 mA Fop Operating Freq Vdd =12V Vdd=10V, Rext=390K ohm 80K HZ 9. External oscillator resistor selection table (Vdd=11V) Rext (ohm) Freq. (Hz) Operating Current 510 K 65.0 K 443 µA 470 K 65.0 K 444 µA 430 K 72.7 K 445 µA 390 K 79.6 K 447 µA 360 K 82.9 K 449 µA 330 K 90.4 K 451 µA This specification is subject to be changed without notice. Please visit our web site for the most updated information. 3 of 5 2005/1/6 Ver. 1.2 MDT75C271 OTP Encoder 10. Application circuit Vdd ROSC 1 OSCR 8 SW3 7 SW2 6 SW1 5 SW0 K3 2 VDD K2 VSS K1 TXD K0 3 4 Vss Transmitter Circuit This specification is subject to be changed without notice. Please visit our web site for the most updated information. 4 of 5 2005/1/6 Ver. 1.2 MDT75C271 OTP Encoder TXD This specification is subject to be changed without notice. Please visit our web site for the most updated information. 5 of 5 2005/1/6 Ver. 1.2