at27c020 1 features ? fast read access time - 55 ns ? low power cmos operation C 100 m a max. standby C 25 ma max. active at 5 mhz ? jedec standard packages C 32-lead 600-mil pdip C 32-lead plcc C 32-lead tsop ? 5v 10% supply ? high-reliability cmos technology C 2,000v esd protection C 200 ma latchup immunity ? rapid ? programming algorithm - 100 m s/byte (typical) ? cmos and ttl compatible inputs and outputs ? integrated product identification code ? commercial and industrial temperature ranges description the at27c020 is a low-power, high performance 2,097,152-bit one-time programma- ble read only memory (otp eprom) organized as 256k by 8 bits. it requires only one 5v power supply in normal read mode operation. any byte can be accessed in less than 55 ns, eliminating the need for speed reducing wait states on high perfor- mance microprocessor systems. in read mode, the at27c020 typically consumes 8 ma. standby mode supply current is typically less than 10 m a. rev. 0570c-bC12/97 2-megabit (256k x 8) otp eprom at27c020 pdip top view 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 vpp a16 a15 a12 a7 a6 a5 a4 a3 a2 a1 a0 o0 o1 o2 gnd vcc pgm a17 a14 a13 a8 a9 a11 oe a10 ce 07 06 05 04 03 tsop top view type 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 a11 a9 a8 a13 a14 a17 pgm vcc vpp a16 a15 a12 a7 a6 a5 a4 oe a10 ce 07 06 05 04 03 gnd 02 01 o0 a0 a1 a2 a3 plcc top view 5 6 7 8 9 10 11 12 13 29 28 27 26 25 24 23 22 21 a7 a6 a5 a4 a3 a2 a1 a0 o0 a14 a13 a8 a9 a11 oe a10 ce 07 4 3 2 1 32 31 30 14 15 16 17 18 19 20 01 02 gnd 03 04 05 06 a12 a15 a16 vpp vcc pgm a17 pin configurations pin name function a0 - a17 addresses o0 - o7 outputs ce chip enable oe output enable pgm program strobe
at27c020 2 the at27c020 is available in a choice of industry standard jedec-approved one-time programmable (otp) plastic pdip, plcc, and tsop packages. all devices feature two- line control (ce , oe ) to give designers the flexibility to pre- vent bus contention. with 256k byte storage capability, the at27c020 allows firmware to be stored reliably and to be accessed by the system without the delays of mass storage media. atmels 27c020 have additional features to ensure high quality and efficient production use. the rapid ? program- ming algorithm reduces the time required to program the part and guarantees reliable programming. programming time is typically only 100 m s/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 programming algorithms and voltages. 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 tran- sients may exceed data sheet limits, resulting in device non-conformance. at a minimum, a 0.1 m f high frequency, low inherent inductance, ceramic capacitor should be uti- lized for each device. this capacitor should be connected between the v cc and ground terminals of the device, as close to the device as possible. additionally, to stabilize the supply voltage level on printed circuit boards with large eprom arrays, a 4.7 m f bulk electrolytic capacitor should be utilized, again connected between the v cc and ground terminals. this capacitor should be positioned as close as possible to the point where the power supply is connected to the array. block diagram
at27c020 3 absolute maximum ratings* temperature under bias.......................-55c to +125c *notice: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. exposure to abso- lute maximum rating conditions for extended periods may affect device reliability. note: 1. minimum voltage is -0.6v dc which may undershoot to -2.0v for pulses of less than 20 ns. maximum output pin voltage is v cc + 0.75v dc which may overshoot to +7.0v for pulses of less than 20 ns. storage temperature............................-65c to +150c voltage on any pin with respect to ground ............................... -2.0v to +7.0v (1) voltage on a9 with respect to ground ............................ -2.0v to +14.0v (1) v pp supply voltage with respect to ground ............................. -2.0v to +14.0v (1) operating modes notes: 1. x can be v il or v ih. 2. refer to programming characteristics. 3. v h = 12.0 0.5v. 4. two identifier bytes may be selected. all ai inputs are held low (v il ), except a9 which is set to v h and a0 which is toggled low (v il ) to select the manufacturers identification byte and high (v ih ) to select the device code byte. mode/pin ce oe pgm ai v pp outputs read v il v il x (1) ai x d out output disable x v ih xxxhigh z standby v ih xxxxhigh z rapid program (2) v il v ih v il ai v pp d in pgm verify v il v il v ih ai v pp d out pgm inhibit v ih xx x v pp high z product identification (4) v il v il x a9 = v h (3) a0 = v ih or v il a1 - a17 = v il x identification code
at27c020 4 ac characteristics for read operation note: 1. 2, 3, 4, 5. see ac waveforms for read operation diagram. symbol parameter at27c020 units -55 -70 -90 -12 -15 condition min max min max min max min max min max t acc (3) address to output delay ce =oe = v il 55 70 90 120 150 ns t ce (2) ce to output delay oe = v il 55 70 90 120 150 ns t oe (2)(3) oe to output delay ce = v il 20 30 35 35 40 ns t df (4)(5) oe or ce high to output float, whichever occurred first 18 20 20 30 40 ns t oh output hold from address, ce or oe ,whichever occurred first 77000 ns dc and ac operating conditions for read operation at27c020 -55 -70 -90 -12 -15 operating temperature (case) com. 0c - 70c 0c - 70c 0c - 70c 0c - 70c 0c - 70c ind. -40 c - 85c -40 c - 85c -40 c - 85c -40 c - 85c -40 c - 85c v cc power supply 5v 10% 5v 10% 5v 10% 5v 10% 5v 10% dc and operating characteristics for read operation notes: 1. v cc must be applied simultaneously or before v pp , and removed simultaneously or after v pp . 2. v pp may be connected directly to v cc except during programming. the supply current would then be the sum of i cc and i pp . symbol parameter condition min max units i li input load current v in = 0v to v cc (com., ind.) 1.0 m a i lo output leakage current v out = 0v to v cc (com., ind.) 5.0 m a i pp (2) v pp (1) read/standby current v pp = v cc 10 m a i sb v cc (1) standby current i sb1 (cmos), ce = v cc 0.3v 100 m a i sb2 (ttl), ce = 2.0 to v cc + 0.5v 1.0 ma i cc v cc active current f = 5 mhz, i out = 0 ma, ce = v il 25 ma v il input low voltage -0.6 0.8 v v ih input high voltage 2.0 v cc + 0.5 v v ol output low voltage i ol = 2.1 ma 0.4 v v oh output high voltage i oh = -400 m a2.4v
at27c020 5 ac waveforms for read operation (1) notes: 1. timing measurement references are 0.8v and 2.0v. input ac drive levels are 0.45v and 2.4v, unless otherwise specified. 2. oe may be delayed up to t ce - t oe after the falling edge of ce without impact on t ce. 3. oe may be delayed up to t acc - t oe after the address is valid without impact on t acc . 4. this parameter is only sampled and is not 100% tested. 5. output float is defined as the point when data is no longer driven. input test waveforms and measurement levels for -55 devices only: t r , t f < 5 ns (10% to 90%) for -70,-90,-12,-15 devices only: t r , t f < 20 ns (10% to 90%) 0.0v 3.0v 1.5v ac driving levels ac measurement level pin capacitance f = 1 mhz, t = 25 c (1) note: 1. typical values for nominal supply voltage. this parameter is only sampled and is not 100% tested. typ max units conditions c in 48pfv in = 0v c out 812pfv out = 0v output test load (1) note: 1. cl = 100 pf including jig capacitance except -55 devices where cl = 30 pf.
at27c020 6 programming waveforms (1) notes: 1. the input timing reference is 0.8v for v il and 2.0v for v ih . 2. t oe and t dfp are characteristics of the device but must be accommodated by the programmer. 3. when programming the at27c020, a 0.1 m f capacitor is required across v pp and ground to suppress voltage transients. dc programming characteristics t a = 25 5c, v cc = 6.5 0.25v, v pp = 13.0 0.25v symbol parameter test conditions limits units min max i li input load current v in = v il , v ih 10 m a v il input low level -0.6 0.8 v v ih input high level 2.0 v cc + 1.0 v v ol output low voltage i ol = 2.1 ma 0.4 v v oh output high voltage i oh = -400 m a2.4 v i cc2 v cc supply current (program and verify) 40 ma i pp2 v pp supply current ce = pgm = v il 20 ma v id a9 product identification voltage 11.5 12.5 v
at27c020 7 ac programming characteristics t a = 25 5c, v cc = 6.5 0.25v,v pp = 13.0 0.25v notes: 1. v cc must be applied simultaneously or before v pp and removed simultaneously or after v pp . 2. this parameter is only sampled and is not 100% tested. output float is defined as the point where data is no longer driven see timing diagram. 3. program pulse width tolerance is 100 m s 5%. symbol parameter test condition (1) limits units min max t as address setup time input rise and fall times: (10% to 90%) 20 ns. input pulse levels: 0.45v to 2.4v input timing reference level: 0.8v to 2.0v output timing reference level: 0.8v to 2.0v 2 m s t ces ce setup time 2 m s t oes oe setup time 2 m s t ds data setup time 2 m s t ah address hold time 0 m s t dh data hold time 2 m s t dfp oe high to output float delay (2) 0 130 ns t vps v pp setup time 2 m s t vcs v cc set up time 2 m s t pw pgm program pulse width (3) 95 105 m s t oe data valid from oe 150 ns t prt v pp pulse rise time during programming 50 ns atmels 27c020 integrated product identification code pins codes a0 o7 o6 o5 o4 o3 o2 o1 o0 hex data manufacturer 000011110 1e device type 110000110 86
at27c020 8 rapid programming algorithm a 100 m s pgm pulse width is used to program. the address is set to the first location. v cc is raised to 6.5v and v pp is raised to 13.0v. each address is first programmed with one 100 m s pgm pulse without verification. then a verification / reprogramming loop is executed for each address. in the event a byte fails to pass verification, up to 10 successive 100 m s pulses are applied with a verification after each pulse. if the byte fails to verify after 10 pulses have been applied, the part is considered failed. after the byte verifies properly, the next address is selected until all have been checked. v pp is then lowered to 5.0v and v cc to 5.0v. all bytes are read again and compared with the origi- nal data to determine if the device passes or fails.
at27c020 9 ordering information t acc (ns) i cc (ma) ordering code package operation range active standby 55 25 0.1 at27c020-55jc at27c020-55pc at27c020-55tc 32j 32p6 32t commercial (0 c to 70 c) 25 0.1 at27c020-55ji at27c020-55pi at27c020-55ti 32j 32p6 32t industrial (-40 c to 85 c) 70 25 0.1 at27c020-70jc at27c020-70pc at27c020-70tc 32j 32p6 32t commercial (0 c to 70 c) 25 0.1 at27c020-70ji at27c020-70pi at27c020-70ti 32j 32p6 32t industrial (-40 c to 85 c) 90 25 0.1 at27c020-90jc at27c020-90pc at27c020-90tc 32j 32p6 32t commercial (0 c to 70 c) 25 0.1 AT27C020-90JI at27c020-90pi at27c020-90ti 32j 32p6 32t industrial (-40 c to 85 c) 120 25 0.1 at27c020-12jc at27c020-12pc at27c020-12tc 32j 32p6 32t commercial (0 c to 70 c) 25 0.1 at27c020-12ji at27c020-12pi at27c020-12ti 32j 32p6 32t industrial (-40 c to 85 c) 150 25 0.1 at27c020-15jc at27c020-15pc at27c020-15tc 32j 32p6 32t commercial (0 c to 70 c) 25 0.1 at27c020-15ji at27c020-15pi at27c020-15ti 32j 32p6 32t industrial (-40 c to 85 c) package type 32j 32-lead,plastic j-leaded chip carrier (plcc) 32p6 32-lead, 0.600" wide, plastic dual inline package (pdip) 32t 32-lead, plastic thin small outline package (tsop)
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