Features Fast read access time 120ns Dual voltage range operation Low voltage power supply range, 3.0V to 3.6V, or Standard power supply range, 5V 10% Compatible with JEDEC standard Atmel AT27C020 Low-power CMOS operation 20A max standby (less than 1A, typical) for V = 3.6V CC 29mW max active at 5MHz for V = 3.6V CC 2Mb (256K x 8) JEDEC standard package Low Voltage, 32-lead PLCC High-reliability CMOS technology One-time 2,000V ESD protection Programmable, 200mA latchup immunity Read-only Memory Rapid programming algorithm 100s/byte (typical) Two-line control CMOS- and TTL-compatible inputs and outputs Atmel AT27LV020A JEDEC standard for LVTTL Integrated product identification code Industrial temperature range Green (Pb/halide-free) packaging option 1. Description The Atmel AT27LV020A is a high-performance, low-power, low-voltage, 2,097,152-bit, one-time programmable, read-only memory (OTP EPROM) organized as 256K by 8 bits. It requires only one supply in the range of 3.0 to 3.6V in normal read mode operation, making it ideal for fast, portable systems using battery power. The Atmel innovative design techniques provide fast speeds that rival 5V parts, while keep- ing the low power consumption of a 3V supply. At V = 3.0V, any byte can be accessed in CC less than 120ns. With a typical power dissipation of only 18mW at 5MHz and V = 3.3V, CC the AT27LV020A consumes less than one-fifth the power of a standard, 5V EPROM. Standby mode supply current is typically less than 1A at 3.3V. The AT27LV020A is available in an industry-standard, JEDEC-approved, one-time program- mable (OTP) PLCC package. All devices feature two-line control (CE, OE) to give designers the flexibility to prevent bus contention. The AT27LV020A operating with V at 3.0V produces TTL-level outputs that are compati- CC ble with standard TTL logic devices operating at V = 5.0V. The device is also capable of CC standard, 5V operation, making it ideally suited for dual supply range systems or card prod- ucts that are pluggable in both 3V and 5V hosts. The AT27LV020A has additional features to ensure high quality and efficient production use. The rapid programming algorithm reduces the time required to program the part and guar- antees reliable programming. Programming time is typically only 100s/byte. The integrated product identification code electronically identifies the device and manufacturer. This feature is used by industry standard programming equipment to select the proper 0549HEPROM4/11programming algorithms and voltages. The AT27LV020A programs in exactly the same way as a standard, 5V Atmel AT27C020, and uses the same programming equipment. 2. Pin configurations 32-lead PLCC Pin name Function Top view A0 - A17 Addresses O0 - O7 Outputs A7 5 29 A14 CE Chip enable A6 6 28 A13 OE Output enable A5 7 27 A8 A4 8 26 A9 PGM Program strobe A3 9 25 A11 A2 10 24 OE NC No connect A1 11 23 A10 A0 12 22 CE O0 13 21 O7 3. System considerations Switching between active and standby conditions via the chip enable pin may produce transient voltage excursions. Unless accommodated by the system design, these transients may exceed datasheet limits, resulting in device nonconformance. At a minimum, a 0.1F, high-frequency, low inherent inductance, ceramic capacitor should be utilized for each device. This capacitor should be connected between the V and ground terminals of the device, as close to the device as possible. CC Additionally, to stabilize the supply voltage level on printed circuit boards with large EPROM arrays, a 4.7F bulk electrolytic capacitor should be utilized, again connected between the V and ground terminals. This capacitor should be positioned as CC close as possible to the point where the power supply is connected to the array. Figure 3-1. Block diagram 2 Atmel AT27LV020A 0549HEPROM4/11 O1 14 4 A12 O2 15 3 A15 GND 16 2 A16 O3 17 1 VPP O4 18 32 VCC O5 19 31 PGM O6 20 30 A17