Am27512_ 65,536 x 8-Bit UV Erasable PROM ersgwy PRELIMINARY DISTINCTIVE CHARACTERISTICS @ Fast access time as low as 250ns @ Separate chip enable and output enable controls @ Programming voltage: 12.5V @ TTL compatible inputs/outputs @ tow Power consumption @ 28-pin JEDEC approved Am27512 pin-out - Active: 525mW @ Pin compatible to Am2764, Am27256, Am27128 - Standby: 132mw EPROMS and Am92256 - 256K ROM @ Single 5V power supply @ Fast programming time @ +10% Vcc supply tolerance available @ Auto select mode for automated programming @ Fully static operation-no clocks GENERAL DESCRIPTION The Am27512 is a 524,288 bit UV-light erasable and To eliminate bus contention in a multi-bus microprocessor electrically programmable read-only memory. it is orga- system, the Am27512 offers separate Output Enable (OE) nized as 65,536 words by 8-bits per word. The standard and Chip Enable (CE) controls. Am27512 offers a fast 250ns access time allowing opera- . . . . . tion with high-speed microprocessors without any WAIT All signals are TTL levels, including programming signals. state. Bit locations may be programmed singly, in blocks or at random. To reduce programming time, the Am27512 may be programmed using 1ms pulses. The Am27512 can be programmed in as little as six minutes. BLOCK DIAGRAM MODE SELECT TABLE Oe VEC DATA OUTPUTS. I t O~= Gno 90-07 Inputs O-- vep { t { { t { { t CE/PGM | OE/Vpp | Ag Output Mode OE | oureutenasie [-~I L L x Dout Read CHP ENABLE ANO OUTPUT BUFFERS ve ~|_Prostoie L H x HIGH z | pulput 4 pectoen - Y-GATING x xX HIGH Z Standby 7 Vpp x DIN Program aoa | | r Program -4 -~ L L x D ANPUTS OUT Verify x . $24,288-BIT * Program _ DECODER . CELL MATRIX H Vpp x HIGH Z inne _ . L L H CODE auto BD000730 PRODUCT SELECTOR GUIDE e / i Pre Zc ( / Ye Part Number Am27512 | Am27512-25) Am27512-3 | Am27512-30 | Am27512-45 Supply Voltage 5V15% 5V110% 5V15% 5Vt 10% 5V+10% Access Time 250ns 300ns 450ns Chip Enable Delay 250ns 300ns 450ns Output Enable Delay 100ns 120ns 150ns 04920BAm27512 CONNECTION DIAGRAM Top View avi? ~~ 2 [vec Av2L 2 27 [J Ana a7Q3 26 LD) Ata AeL]4 25 [] As asfls 24 [] Ag a 6 23 al AsLi7 22 /Vpp Aste A272 0 Dato a9 20 (1) CE/PGM AoC] 10 to LJ 07 Co] 11 1e DF % oi 12 17 [DOs 021) 13 16 [J % ann] 44 15 [.] O3 CDO0096A Note: Pin 1 is marked for orientation Ag- As: Address Og -O7: Outputs OE/Vpp: Output Enable/Vpp CE/PGM: Chip Enable/Program ORDERING INFORMATION Am27512-25 D C Temperature Package D - 28-pin CERDIP Speed Select No code Am27512-25 }250ns Am27512-3 Am27512-30 }300ns Am27512-45 450ns Device Type 8-bit UV erasable PROM CG - Commercial (0C to + 70C) | - Industrial (-40C to +85C) No Code DC, DI L - Extended (-55C to + 100C) Am27512-25 | pr ow M- Military (-55C to + 125C) Valid Combinations Am27512-3 Am27512-30 | DC DI, DL Am27512-45 04920BERASING THE Am27512 In order to clear ali locations of their programmed contents, it is necessary to expose the Am27512 to an ultraviolet light source. A dosage of 15 Wseconds/cm? is required to com- pletely erase an Am27512. This dosage can be obtained by exposure to an ultraviolet lamp [(wavelength of 2537 Ang- stroms (A}] with intensity of 12000uW/cm? for 15 to 20 minutes. The Am27512 should be about ene inch from the source and all filters should be removed from the UV light source prior to erasure. It is important to note that the Am27512, and similar devices, will erase with light sources having wavelengths shorter than 4000 Angstroms. Although erasure times will be much longer than with UV sources at 2537A, nevertheless the exposure to fluorescent light and sunlight will eventually erase the Am27512 and exposure to them should be prevented to realize maximum system reliability. If used in such an environ- ment, the package window should be covered by an opaque label or substance. PROGRAMMING THE Am27512 Upon delivery, or after each erasure, the Am27512 has all 65,536 bytes in the ''1," or high state. ''0''s are loaded into the Am27512 through the procedure of programming. The programming mode is entered when 12.5V is applied to the OE/Vpp pin, and CE/PGM is at TTL-low. The data to be programmed is applied 8 bits in parallel ta the data output pins. The flow chart on Page 6 shows the Interactive Programming Algorithm. Interactive algorithms reduce programming time by using short (1ms) program pulses and giving each address only as many pulses as necessary in order to reliably program the data. After each pulse is applied to a given address, the data in that address is verified. If the data does not verify, an additional pulse is applied for a maximum of 25 pulses. This process is repeated while sequencing through each address of the Am27512. This part of the algorithm is done at Voc = 6.0V to assure that each EPROM bit is programmed to a sufficiently high threshold voltage. After the entire memory has been programmed with the 1ms program pulse, the entire memory is given an additional 'overpragram by cycling through each address and applying an additional 2ms program pulse. After the final address is completed, the entire EPROM memory is verified at Voc = 5V5%. AUTO SELECT MODE The Auto Select mode allows the reading out of a binary code from an EPROM that will identity its manufacturer and type. This mode is intended for use by programming equipment for the purpose of automatically matching the device to be programmed with its corresponding programming algorithm. This mode is functional in the 25C +5C ambient temperature range that is required when programming the Am27512. To activate this mode, the programming equipment must force 11.5 to 12.5V on address line App(pin 24) of the Am27512. Two identifier bytes may then be sequenced from the device outputs by toggling address line Ap (pin 10) from Vj,_ to Vi}. All other address lines must be held at Vj, during Auto Select Mode. Byte 0 (Ao = Vi_) represents the manufacturer code and byte 1 (Ag = Vi) the device identifier code. For the Am27512 these two identifier bytes are given in the table on the next page. All identifiers for manufacturer and device codes will possess odd parity, with the MSB (07) defined as the Parity bit. READ MODE The Am27512 has two control functions, bath of which must be logically satisfied in order to obtain data at the outputs. Chip Enable (CE) is the power control and should be used for device selection. Output Enable (OE) is the output control and should be used to gate data to the output pins, indapendent of device selection. Assuming that addresses are stable, address access time (tacc) is equal to the delay from CE to output (tce). Data is available at the outputs tog after the falling edge of OE, assuming that CE has been low and addresses have been stable for at least tacc toe. STANDBY MODE The Am27512 has a standby mode which reduces the active power dissipation by 75% from 525mW to 132mW (values for 0 to + 70C). The Am27512 is placed in the standby mode by applying a TTL high signal to the CE input. When in standby mode, the outputs are in a high impedance state, independent of the OE input. OUTPUT OR-TIEING To accommodate multiple memory connections, a 2 line control function is provided to allow for: 1. Low memory power dissipation 2. Assurance that output bus contention will not occur. It is recommended that TE be decoded and used as the primary device selecting function, while OE be made a common connection to all devices in the array and connected to tha READ line from the system control bus. This assures that all deselected memory devices are in their low-power standby mode and that the output pins are only active when data is desired from a particular memory device. PROGRAM INHIBIT Programming of multiple Am27512s in parallel with different data is also easily accomplished. Except for CE/PGM, all like inputs including OE/Vpp of the parallel Am27512s may be common. A TTL low-level program pulse applied to an Am27512s CE/PGM input with OE/Vpp at 12.5V will program that Am27512. A high-level CE/PGM inputs inhibits the other Am27512s from being programmed. PROGRAM VERIFY A verify should be performed on the programmed bits to determine that they were correctly programmed. The verify must be performed with OE/Vpp and CE/PGM at Vi. Data should be verified tpy after the falling edge of CE. SYSTEM APPLICATIONS During the switch between active and standby conditions, transient current peaks are produced on the rising and falling edges of chip enable. The magnitude of these transient current peaks is dependent on the output capacitance loading of the device. A 0.1uF ceramic capacitor (high frequency, low inherent inductance) should be used on each device between Vcc and GND to minimize transient effects. In addition, to overcome the voltage droop caused by the inductive effects of the printed circuit board traces on EPROM arrays, a 4.7 uF bulk electrolytic capacitor should be used between Vcc and GND for each eight devices. The location of the capacitor should be close to where the power supply is connected to the array. 04920B zigZzewyAm27512 ABSOLUTE MAXIMUM RATINGS Storage Temperature ...............ccceeeeeee -65C to + 150C Ambient Temperature with Power Applied ................ccccsceseecees -10C to +135C Voltage on All Inputs and Voc with Respect to GND .......... ee +6.25V to 0.6V Vpp Supply Voltage with Respect to Ground During Programming.......... +13.5V to -0.6V Voltage on Pin 24 with Respect HO Ground 2... cece eteee cence eee +13.5V to -0.6V Stresses above those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent device failure. Functionality at or above these limits is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability. OPERATING RANGES Temperature Commercial ..............cccccescesecneeereeeess 0C to +70C Industrial ... 40C to +85C Extended .. ..- 85C to + 100C Military 0.0.0... cece ccc eeeesnce een evnee -5C to +125C Supply Voltages AM27512, -3, -4 cee eeceeceteeeteeeeees +4.75V to +5.25V Am27512, -25, -30, vee $4.5V to +5.5V Operating ranges define those limits over which the function- ality of the device is guaranteed. DC CHARACTERISTICS over operating range unless otherwise specified Symbol Parameter Test Conditions Min Typ Max Units lu Input Load Current Vin OV to 5.5V 10 BA ILo Output Leakage Current Vout = OV to 5.5V 10 BA loct Voc Standby Current (Note 5) CE = Vin, OF = Vic . = mA C devices 100 loce Voc Active Current (Note 5) OE = CE =ViL M devices 120 mA Vit Input Low Voltage -041 +08 Volts Vin input High Voltage 2.0 Voct 1 Volts VoL Output Low Voltage lo, = 2.1mA 0.45 Volts Vou Output High Voitage lon = - 400pA 24 Volts CIN Input Capacitance Vin = OV {Note 3) 7 pF Cout Output Capacitance Vout = 0V (Note 3) 8 12 pF Cine OE/Vpp Input Capacitance Vin = OV (Note 3) 12 20 pF Cina CE/PGM input Capacitance Vin = OV (Note 3) 9 12 pF Notes: 1. Voc must be applied simultaneously or before Vpp and removed simultaneously or after Vpp. 2. Typical values are for nominal supply voltages. 3. This parameter is only sampled and not 100% tested. 4. Caution: The Am27512 must not be removed from or inserted into a socket or board when Vpp or Vpp is applied. 5. Ioc1 max is 40mA and Ioc2 max is 120mA for Am27512- 45. IDENTIFIER BYTES Ao O7 O65 Os O4 03 O2 O1 Oo Hex Identifier (10) | (19) | (18) | (a7) | (16) | (15) | (13) | 12) | 11) | Data Manufacturer Code L 0 0 0 0 0 Q 0 1 01 Device Code 1 0 0 Qa QO 1 0 1 85 Notes: 1. Ag = 12.0V +0.5V. 2. Aj Ag, Aig- Ais, CE, OF = VL. 3. A14=Don't Care. 049208INTERACTIVE PROGRAMMING FLOW CHART aezgwiy START ADDR = FIRST LOCATION Voc = 6.0 OE/Vpp = 13.0V INTERACTIVE SECTION wo INCREMENT AODRESS Yes FAL ADORESS = FIRST LOCATION Voc = 5.0 Ice Sepp = 13.0 OVERPROGRAM SECTION PROGRAM ONE 2MS PULSE INCREMENT AODRESS Voc = 5.0V = 5% OE/Vpp = Vin VERIFY SECTION VERIFY ALL BYTES DEVICE FAILEO PFOO0250 049208Am27512 INTERACTIVE PROGRAMMING ALGORITHM DC PROGRAMMING CHARACTERISTICS Symbol Parameter Test Conditions Min Max | Units lu Input Current (All Inputs) VIN= ViL oF Vin. 10 LA VoL Output Low Voltage During Verify lol = 2.1 mA 0.45 Volts VoH Output High Voltage During Verify lon =- 400pA 2.4 Volts loc Voc Supply Current (Program and Verify) 150 mA VIL Input Low Level (All Inputs) ~0.1 0.8 Volts Vin Input High Level (All Inputs Except OE/Vpp) 20 | Voct1 | Voits Ipp Vpp Supply Current (Program) CE =ViL, OE/Vpp = 12.5V 30 mA Vio Ag Auto Select Voltage 11.5 12.5 Volts SWITCHING PROGRAMMING CHARACTERISTICS Symbol Parameter Test Conditions Min Max | Units tas Address Setup Time 2 us toes Output Enable Setup Time 2 nS tos Data Setup Time 2 Bs tAH Address Hold Time 2 us 1OEH Output Enable Hold Time Input tR and tF (10% to 90%) = 20ns 2 HS 1DH Data Hold Time Input Signal Levels = 0.8 to 2.2V 2 us Timing Measurement Reference Level: ipF (Note 2) Chip Enable to Output Float Delay inputs: 1V and 2V 0 150 ns tov (Note 2) | Data Valid from CE CE = Vy. OF = Vi) Outputs: 0.8V and 2V 450 ns tpw Program Pulse Width 96 3.15 ms tpAT Program Pulse Rise Time 50 ns tvA Vpp Recovery Time 2 uS tycs Voc Setup Time 2 uS Notes: __ 1. When programming the Am27512, a 0.1yF capacitor is required across OE/Vpp and ground to suppress spurious voltage transients which may damage the device. 2. This parameter is only sampled and is not 100% tested. 04920B 6-64PROGRAM WAVEFORMS DATA IN STABLE DATA OUT VALIO AGO. N A00. N Notes: 1. All times shown in () are minimum in ysec unless otherwise specified. tOF (0.15) MAX WF001330 2. tpy and tpr are characteristics at the device but must be accommodated by the programmer. 6-65 049208 zis.zwyAm27512 SWITCHING TEST CIRCUIT OUTPUT 2.7K UNDER TEST S.0v Cc 6.2K DIODES IN3064 OR EQUIVALENT TCo0025R Cy = 100pF, including jig capacitance. SWITCHING CHARACTERISTICS over operating range unless otherwise specified Min Values Maximum Values / All | 27512-25 | 27512-30 : No. | Symbol Description Test Conditions Types | 27512 | 27512-3 | 27512-45| Units 1 tacc Address to Output Delay Output load: 1TTL CE = OF = Vy 260 | 300 } 450, : | as i f gate and C_ = 100pF ~ ~ 2 toe chip Enable to input Rise and Fall OE = Vit 250 300 450 ns Output Delay Times < 20ns Output Enable Input Pulse Levels: = 3 oe to Output Delay 0.45 to 2.4V CE= Vin 100 120 150 ns t Output Enable High Timing Measurement DF utput Enable Hig! Reference Level: = 4 | tnote 3) | to Output float inputs: CE= Vin 60 105 130 ns 1V and 2Vv Output Hold from : 5 | uty, | Addresses,CE ordE Oy ov CE = OF = Vy 0 ns o Whichever Occured First . SWITCHING WAVEFORMS 24 2.0 ADDRESSES ADDRESSES VALID 08 0.45 n tOE (NOTE 1) f tACC (NOTE 1} | ton ro i HIGH 2 1/7/7777 ouTPuT | VaLIO WAY ouTPuT Notes: 1. OE may be delayed up to tacctog after the falling edge of OE without impact on tacc. 2. tpF is specified from OE or CE, whichever occurs first. WF001320 6-66 04920B