Licensed Intel second source CAT28F020 2 Megabit CMOS Flash Memory FEATURES ■ Commercial, Industrial and Automotive ■ Fast Read Access Time: 70/90/120 ns Temperature Ranges ■ Low Power CMOS Dissipation: ■ Stop Timer for Program/Erase – Active: 30 mA max (CMOS/TTL levels) – Standby: 1 mA max (TTL levels) – Standby: 100 µA max (CMOS levels) ■ On-Chip Address and Data Latches ■ JEDEC Standard Pinouts: – 32-pin DIP – 32-pin PLCC – 32-pin TSOP (8 x 20) ■ High Speed Programming: – 10 µs per byte – 4 Seconds Typical Chip Program ■ 100,000 Program/Erase Cycles ■ 0.5 Seconds Typical Chip-Erase ■ 12.0V ■ 10 Year Data Retention ± 5% Programming and Erase Voltage ■ Electronic Signature DESCRIPTION using a two write cycle scheme. Address and Data are latched to free the I/O bus and address bus during the write operation. The CAT28F020 is a high speed 256K x 8-bit electrically erasable and reprogrammable Flash memory ideally suited for applications requiring in-system or after-sale code updates. Electrical erasure of the full memory contents is achieved typically within 0.5 second. The CAT28F020 is manufactured using Catalyst’s advanced CMOS floating gate technology. It is designed to endure 100,000 program/erase cycles and has a data retention of 10 years. The device is available in JEDEC approved 32-pin plastic DIP, 32-pin PLCC or 32-pin TSOP packages. It is pin and Read timing compatible with standard EPROM and E2PROM devices. Programming and Erase are performed through an operation and verify algorithm. The instructions are input via the I/O bus, BLOCK DIAGRAM I/O0–I/O7 I/O BUFFERS ERASE VOLTAGE SWITCH WE COMMAND REGISTER PROGRAM VOLTAGE SWITCH CE, OE LOGIC DATA LATCH SENSE AMP CE ADDRESS LATCH OE A0–A17 Y-GATING Y-DECODER X-DECODER VOLTAGE VERIFY SWITCH © 1998 by Catalyst Semiconductor, Inc. Characteristics subject to change without notice 2,097,152 BIT MEMORY ARRAY 5115 FHD F02 1 Doc. No. 25037-00 2/98 F-1 CAT28F020 PIN CONFIGURATION PLCC Package (N) 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 VCC WE A17 A14 A13 A8 A9 A11 OE A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 A7 A6 A5 A4 A3 A2 A1 A0 I/O0 4 3 2 1 32 31 30 5 29 6 28 7 27 8 26 9 25 10 24 11 23 12 22 13 21 14 15 16 17 18 19 20 A14 A13 A8 A9 A11 OE A10 CE I/O7 Pin Name Type Function A0–A17 Input Address Inputs for memory addressing I/O0–I/O7 I/O Data Input/Output CE Input Chip Enable OE Input Output Enable WE Input Write Enable VCC Voltage Supply VSS Ground VPP Program/Erase Voltage Supply I/O1 I/O2 VSS I/O3 I/O4 I/O5 I/O6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 A12 A15 A16 VPP VCC WE A17 DIP Package (P) VPP A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 I/O0 I/O1 I/O2 VSS PIN FUNCTIONS 5115 FHD F01 TSOP Package (Standard Pinout) (T) A11 A9 A8 A13 A14 A17 WE VCC VPP A16 A15 A12 A7 A6 A5 A4 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 OE A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 VSS I/O2 I/O1 I/O0 A0 A1 A2 A3 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 A11 A9 A8 A13 A14 A17 WE VCC VPP A16 A15 A12 A7 A6 A5 A4 TSOP Package (Reverse Pinout) (TR) OE A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 VSS I/O2 I/O1 I/O0 A0 A1 A2 A3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 5115 FHD F14 Doc. No. 25037-00 2/98 F-1 2 CAT28F020 ABSOLUTE MAXIMUM RATINGS* *COMMENT Temperature Under Bias ................... –55°C to +95°C Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. Storage Temperature ....................... –65°C to +150°C Voltage on Any Pin with Respect to Ground(1) ........... –2.0V to +VCC + 2.0V Voltage on Pin A9 with Respect to Ground(1) ................... –2.0V to +13.5V VPP with Respect to Ground during Program/Erase(1) .............. –2.0V to +14.0V VCC with Respect to Ground(1) ............ –2.0V to +7.0V Package Power Dissipation Capability (TA = 25°C) .................................. 1.0 W Lead Soldering Temperature (10 secs) ............ 300°C Output Short Circuit Current(2) ........................ 100 mA RELIABILITY CHARACTERISTICS Symbol NEND (3) Parameter Endurance Min. Max. Units Test Method 100K Cycles/Byte MIL-STD-883, Test Method 1033 10 Years MIL-STD-883, Test Method 1008 MIL-STD-883, Test Method 3015 TDR(3) Data Retention VZAP(3) ESD Susceptibility 2000 Volts ILTH(3)(4) Latch-Up 100 mA JEDEC Standard 17 CAPACITANCE TA = 25°C, f = 1.0 MHz Limits Symbol Test Min Max. Units Conditions CIN(3) Input Pin Capacitance 6 pF VIN = 0V COUT(3) Output Pin Capacitance 10 pF VOUT = 0V CVPP(3) VPP Supply Capacitance 25 pF VPP = 0V Note: (1) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns. Maximum DC voltage on output pins is VCC +0.5V, which may overshoot to VCC + 2.0V for periods of less than 20ns. (2) Output shorted for no more than one second. No more than one output shorted at a time. (3) This parameter is tested initially and after a design or process change that affects the parameter. (4) Latch-up protection is provided for stresses up to 100 mA on address and data pins from –1V to VCC +1V. 3 Doc. No. 25037-00 2/98 F-1 CAT28F020 D.C. OPERATING CHARACTERISTICS VCC = +5V ±10%, unless otherwise specified. Limits Symbol Parameter Min. Max. Unit Test Conditions ILI Input Leakage Current ±1 µA VIN = VCC or VSS VCC = 5.5V, OE = VIH ILO Output Leakage Current ±1 µA VOUT = VCC or VSS, VCC = 5.5V, OE = VIH ISB1 VCC Standby Current CMOS 100 µA CE = VCC ±0.5V, VCC = 5.5V ISB2 VCC Standby Current TTL 1 mA CE = VIH, VCC = 5.5V ICC1 VCC Active Read Current 30 mA VCC = 5.5V, CE = VIL, IOUT = 0mA, f = 6 MHz ICC2(1) VCC Programming Current 15 mA VCC = 5.5V, Programming in Progress ICC3(1) VCC Erase Current 15 mA VCC = 5.5V, Erasure in Progress ICC4(1) VCC Prog./Erase Verify Current 15 mA VCC = 5.5V, Program or Erase Verify in Progress IPPS VPP Standby Current ±10 µA VPP = VPPL IPP1 VPP Read Current 200 µA VPP = VPPH IPP2(1) VPP Programming Current 30 mA VPP = VPPH, Programming in Progress IPP3(1) VPP Erase Current 30 mA VPP = VPPH, Erasure in Progress IPP4(1) VPP Prog./Erase Verify Current 5 mA VPP = VPPH, Program or Erase Verify in Progress VIL Input Low Level TTL –0.5 0.8 V VILC Input Low Level CMOS –0.5 0.8 V VOL Output Low Level 0.45 V VIH Input High Level TTL 2 VCC+0.5 V VIHC Input High Level CMOS VCC*0.7 VCC+0.5 V VOH1 Output High Level TTL 2.4 V IOH = –2.5mA, VCC = 4.5V VOH2 Output High Level CMOS VCC–0.4 V IOH = –400µA, VCC = 4.5V VID A9 Signature Voltage 13 V A9 = VID 200 µA A9 = VID IID (1) VLO 11.4 A9 Signature Current VCC Erase/Prog. Lockout Voltage 2.5 V Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. Doc. No. 25037-00 2/98 F-1 4 IOL = 5.8mA, VCC = 4.5V CAT28F020 SUPPLY CHARACTERISTICS Limits Symbol Parameter VCC VCC Supply Voltage VPPL VPP During Read Operations VPPH VPP During Read/Erase/Program Min Max. Unit 4.5 5.5 V 0 6.5 V 11.4 12.6 V A.C. CHARACTERISTICS, Read Operation VCC = +5V ±10%, unless otherwise specified. JEDEC Standard Symbol Symbol 28F020-70(8) Parameter Min. Max. 28F020-90 (7) 28F020-12(7) Min. Max. 90 Min. Max. Unit tAVAV tRC Read Cycle Time tELQV tCE CE Access Time 70 90 120 ns tAVQV tACC Address Access Time 70 90 120 ns tGLQV tOE OE Access Time 28 35 50 ns tAXQX tOH Output Hold from Address OE/CE Change tGLQX tOLZ(1)(6) 70 OE to Output in Low-Z 120 ns 0 0 0 ns 0 0 0 ns 0 0 0 ns (1)(6) CE to Output in Low-Z tGHQZ tDF (1)(2) OE High to Output High-Z 20 30 30 ns tEHQZ tDF(1)(2) CE High to Output High-Z 30 40 40 ns tELQX tWHGL(1) tLZ - 6 Write Recovery Time Before Read 6 µs 6 Figure 1. A.C. Testing Input/Output Waveform(3)(4)(5) Figure 2. Highspeed A.C. Testing Input/Output Waveform(3)(4)(5) 2.4 V 3.0 V 2.0 V INPUT PULSE LEVELS INPUT PULSE LEVELS REFERENCE POINTS 0.8 V 0.45 V Testing Load Circuit (example) Testing Load Circuit (example) 1.3V 1.3V 1N914 1N914 3.3K DEVICE UNDER TEST REFERENCE POINTS 1.5 V 0.0 V 3.3K DEVICE UNDER TEST OUT CL = 100 pF CL INCLUDES JIG CAPACITANCE OUT CL = 30 pF CL INCLUDES JIG CAPACITANCE Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) Output floating (High-Z) is defined as the state where the external data line is no longer driven by the output buffer. (3) Input Rise and Fall Times (10% to 90%) < 10 ns. (4) Input Pulse Levels = 0.45V and 2.4V. For High Speed Input Pulse Levels 0.0V and 3.0V. (5) Input and Output Timing Reference = 0.8V and 2.0V. For High Speed Input and Output Timing Reference = 1.5V. (6) Low-Z is defined as the state where the external data may be driven by the output buffer but may not be valid. (7) For load and reference points, see Fig. 1 (8) For load and reference points, see Fig. 2 5 Doc. No. 25037-00 2/98 F-1 CAT28F020 A.C. CHARACTERISTICS, Program/Erase Operation VCC = +5V ±10%, unless otherwise specified. JEDEC Standard Symbol Symbol 28F020-70 Parameter tAVAV tWC Write Cycle Time tAVWL tAS tWLAX Min. Max. 28F020-90 Min. Max. 28F020-12 Min. Max. Unit 70 90 120 ns Address Setup Time 0 0 0 ns tAH Address Hold Time 40 40 40 ns tDVWH tDS Data Setup Time 40 40 40 ns tWHDX tDH Data Hold Time 10 10 10 ns tELWL tCS CE Setup Time 0 0 0 ns tWHEH tCH CE Hold Time 0 0 0 ns tWLWH tWP WE Pulse Width 40 40 40 ns tWHWL tWPH WE High Pulse Width 20 20 20 ns tWHWH1 (2) - Program Pulse Width 10 10 10 µs tWHWH2 (2) - Erase Pulse Width 9.5 9.5 9.5 ms tWHGL - Write Recovery Time Before Read 6 6 6 µs tGHWL - Read Recovery Time Before Write 0 0 0 µs tVPEL - VPP Setup Time to CE 100 100 100 ns ERASE AND PROGRAMMING PERFORMANCE(1) 28F020-70 Parameter Chip Erase Time(3)(5) Chip Program Time(3)(4) Min. 28F020-90 Typ. Max. 0.5 4 Min. 28F020-12 Typ. Max. 10 0.5 25 4 Min. Typ. Max. Unit 10 0.5 10 sec 25 4 25 sec Note: (1) Please refer to Supply characteristics for the value of VPPH and VPPL. The VPP supply can be either hardwired or switched. If VPP is switched, VPPL can be ground, less than VCC + 2.0V or a no connect with a resistor tied to ground. (2) Program and Erase operations are controlled by internal stop timers. (3) ‘Typicals’ are not guaranteed, but based on characterization data. Data taken at 25°C, 12.0V VPP. (4) Minimum byte programming time (excluding system overhead) is 16 µs (10 µs program + 6 µs write recovery), while maximum is 400 µs/ byte (16 µs x 25 loops). Max chip programming time is specified lower than the worst case allowed by the programming algorithm since most bytes program significantly faster than the worst case byte. (5) Excludes 00H Programming prior to Erasure. Doc. No. 25037-00 2/98 F-1 6 CAT28F020 FUNCTION TABLE(1) Pins Mode CE OE WE VPP I/O Notes Read VIL VIL VIH VPPL DOUT Output Disable VIL VIH VIH X High-Z Standby VIH X X VPPL High-Z Signature (MFG) VIL VIL VIH X 31H A0 = VIL, A9 = 12V Signature (Device) VIL VIL VIH X BDH A0 = VIH, A9 = 12V Program/Erase VIL VIH VIL VPPH DIN See Command Table Write Cycle VIL VIH VIL VPPH DIN During Write Cycle Read Cycle VIL VIL VIH VPPH DOUT During Write Cycle WRITE COMMAND TABLE Commands are written into the command register in one or two write cycles. The command register can be altered only when VPP is high and the instruction byte is latched on the rising edge of WE. Write cycles also internally latch addresses and data required for programming and erase operations. Pins First Bus Cycle Mode Second Bus Cycle Operation Address DIN Operation Address DIN DOUT Set Read Write X 00H Read AIN DOUT Read Sig. (MFG) Write X 90H Read 00 31H Read Sig. (Device) Write X 90H Read 01 BDH Erase Write X 20H Write X Erase Verify Write AIN A0H Read X Program Write X 40H Write AIN Program Verify Write X C0H Read X Reset Write X FFH Write X 20H DOUT DIN DOUT FFH Note: (1) Logic Levels: X = Logic ‘Do not care’ (VIH, VIL, VPPL, VPPH) 7 Doc. No. 25037-00 2/98 F-1 CAT28F020 The conventional mode is entered as a regular READ mode by driving the CE and OE pins low (with WE high), and applying the required high voltage on address pin A9 while all other address lines are held at VIL. READ OPERATIONS Read Mode A Read operation is performed with both CE and OE low and with WE high. VPP can be either high or low, however, if VPP is high, the Set READ command has to be sent before reading data (see Write Operations). The data retrieved from the I/O pins reflects the contents of the memory location corresponding to the state of the 18 address pins. The respective timing waveforms for the read operation are shown in Figure 3. Refer to the AC Read characteristics for specific timing parameters. A Read cycle from address 0000H retrieves the binary code for the IC manufacturer on outputs I/O0 to I/O7: CATALYST Code = 00110001 (31H) A Read cycle from address 0001H retrieves the binary code for the device on outputs I/O0 to I/O7. 28F020 Code = 1011 1101 (BDH) Signature Mode Standby Mode The signature mode allows the user to identify the IC manufacturer and the type of device while the device resides in the target system. This mode can be activated in either of two ways; through the conventional method of applying a high voltage (12V) to address pin A9 or by sending an instruction to the command register (see Write Operations). With CE at a logic-high level, the CAT28F020 is placed in a standby mode where most of the device circuitry is disabled, thereby substantially reducing power consumption. The outputs are placed in a high-impedance state. Figure 3. A.C. Timing for Read Operation POWER UP STANDBY DEVICE AND ADDRESS SELECTION ADDRESSES OUPUTS ENABLED DATA VALID STANDBY POWER DOWN ADDRESS STABLE tAVAV (tRC) CE (E) tEHQZ (tDF) OE (G) tWHGL tGHQZ (tDF) tGLQV (tOE) WE (W) tELQV (tCE) tAXQX (tOH) tGLQX (tOLZ) tELQX (tLZ) HIGH-Z HIGH-Z DATA (I/O) OUTPUT VALID tAVQV (tACC) 28F020 F05 Doc. No. 25037-00 2/98 F-1 8 CAT28F020 A Read cycle from address 0001H retrieves the binary code for the device on outputs I/O0 to I/O7. WRITE OPERATIONS The following operations are initiated by observing the sequence specified in the Write Command Table. 28F020 Code = 1011 1101 (BDH) Read Mode Erase Mode The device can be put into a standard READ mode by initiating a write cycle with 00H on the data bus. The subsequent read cycles will be performed similar to a standard EPROM or E2PROM Read. During the first Write cycle, the command 20H is written into the command register. In order to commence the erase operation, the identical command of 20H has to be written again into the register. This two-step process ensures against accidental erasure of the memory contents. The final erase cycle will be stopped at the rising edge of WE, at which time the Erase Verify command (A0H) is sent to the command register. During this cycle, the address to be verified is sent to the address bus and latched when WE goes low. An integrated stop timer allows for automatic timing control over this operation, eliminating the need for a maximum erase timing specification. Refer to AC Characteristics (Program/Erase) for specific timing parameters. Signature Mode An alternative method for reading device signature (see Read Operations Signature Mode), is initiated by writing the code 90H into the command register while keeping VPP high. A read cycle from address 0000H with CE and OE low (and WE high) will output the device signature. CATALYST Code = 00110001 (31H) Figure 4. A.C. Timing for Erase Operation VCC POWER-UP & STANDBY SETUP ERASE COMMAND ERASE COMMAND ERASING ERASE VERIFY COMMAND ERASE VCC POWER-DOWN/ VERIFICATION STANDBY ADDRESSES tWC tWC tWC tAS tRC tAH CE (E) tCH tCS tCH tCS tCH tEHQZ OE (G) tGHWL tWHWH2 tWPH tDF tWHGL WE (W) tWP tDS HIGH-Z DATA IN = 20H DATA (I/O) tDH tDS tWP tDH DATA IN = 20H tWP tDS tDH tOE DATA IN = A0H tLZ tCE VCC VALID DATA OUT 5.0V 0V VPP tOH tOLZ tVPEL VPPH VPPL 28F020 F11 9 Doc. No. 25037-00 2/98 F-1 CAT28F020 Figure 5. Chip Erase Algorithm(1) BUS OPERATION COMMAND START ERASURE COMMENTS VPP RAMPS TO VPPH (OR VPP HARDWIRED) APPLY VPPH PROGRAM ALL BYTES TO 00H ALL BYTES SHALL BE PROGRAMMED TO 00 BEFORE AN ERASE OPERATION STANDBY INITIALIZE ADDRESS INITIALIZE ADDRESS INITIALIZE PLSCNT = 0 PLSCNT = PULSE COUNT WRITE ERASE SETUP COMMAND WRITE ERASE ACTUAL ERASE NEEDS 10ms PULSE, DATA=20H DATA = 20H WRITE ERASE COMMAND WRITE ERASE DATA = 20H DATA = 20H WAIT TIME OUT 10ms WRITE ERASE VERIFY COMMAND WRITE ERASE VERIFY TIME OUT 6µs ADDRESS = BYTE TO VERIFY DATA = 20H; A0H STOPS ERASE OPERATION WAIT INCREMENT ADDRESS READ DATA FROM DEVICE READ READ BYTE TO VERIFY ERASURE STANDBY COMPARE OUTPUT TO FF INCREMENT PULSE COUNT NO DATA = FFH? YES NO NO INC PLSCNT ==1000 3000 ?? YES LAST ADDRESS? YES WRITE READ COMMAND WRITE APPLY VPPL APPLY VPPL ERASURE COMPLETED ERASE ERROR STANDBY Note: (1) The algorithm MUST BE FOLLOWED to ensure proper and reliable operation of the device. Doc. No. 25037-00 2/98 F-1 10 READ DATA = 00H RESETS THE REGISTER FOR READ OPERATION VPP RAMPS TO VPPL (OR VPP HARDWIRED) 5108 FHD F10 CAT28F020 Erase-Verify Mode Program-Verify Mode The Erase-verify operation is performed on every byte after each erase pulse to verify that the bits have been erased. A Program-verify cycle is performed to ensure that all bits have been correctly programmed following each byte programming operation. The specific address is already latched from the write cycle just completed, and stays latched until the verify is completed. The Programverify operation is initiated by writing C0H into the command register. An internal reference generates the necessary high voltages so that the user does not need to modify VCC. Refer to AC Characteristics (Program/ Erase) for specific timing parameters. Programming Mode The programming operation is initiated using the programming algorithm of Figure 7. During the first write cycle, the command 40H is written into the command register. During the second write cycle, the address of the memory location to be programmed is latched on the falling edge of WE, while the data is latched on the rising edge of WE. The program operation terminates with the next rising edge of WE. An integrated stop timer allows for automatic timing control over this operation, eliminating the need for a maximum program timing specification. Refer to AC Characteristics (Program/Erase) for specific timing parameters. Figure 6. A.C. Timing for Programming Operation PROGRAM VCC POWER-UP SETUP PROGRAM LATCH ADDRESS COMMAND & DATA VERIFY & STANDBY PROGRAMMING COMMAND PROGRAM VCC POWER-DOWN/ VERIFICATION STANDBY ADDRESSES tWC tWC tAS tRC tAH CE (E) tCH tCS tCH tCS tCH tEHQZ OE (G) tGHWL tWHWH1 tWPH tDF tWHGL WE (W) tWP tDS HIGH-Z DATA IN = 40H DATA (I/O) tDH tDS tWP tDH tWP tDS tDH tOE DATA IN = C0H DATA IN tLZ tCE VCC VALID DATA OUT 5.0V 0V VPP tOH tOLZ tVPEL VPPH VPPL 28F020 F07 11 Doc. No. 25037-00 2/98 F-1 CAT28F020 Figure 7. Programming Algorithm(1) START PROGRAMMING BUS OPERATION APPLY VPPH STANDBY COMMAND COMMENTS VPP RAMPS TO VPPH (OR VPP HARDWIRED) INITIALIZE ADDRESS INITIALIZE ADDRESS PLSCNT = 0 INITIALIZE PULSE COUNT PLSCNT = PULSE COUNT WRITE SETUP PROG. COMMAND 1ST WRITE CYCLE WRITE SETUP DATA = 40H WRITE PROG. CMD ADDR AND DATA 2ND WRITE CYCLE PROGRAM VALID ADDRESS AND DATA TIME OUT 10µs WAIT WRITE PROGRAM VERIFY COMMAND 1ST WRITE CYCLE PROGRAM VERIFY TIME OUT 6µs DATA = C0H WAIT READ DATA FROM DEVICE READ READ BYTE TO VERIFY PROGRAMMING STANDBY COMPARE DATA OUTPUT TO DATA EXPECTED NO VERIFY DATA ? YES INCREMENT ADDRESS NO NO INC PLSCNT = 25 ? YES LAST ADDRESS? YES WRITE READ COMMAND 1ST WRITE CYCLE APPLY VPPL APPLY VPPL PROGRAMMING COMPLETED PROGRAM ERROR STANDBY READ DATA = 00H SETS THE REGISTER FOR READ OPERATION VPP RAMPS TO VPPL (OR VPP HARDWIRED) Note: (1) The algorithm MUST BE FOLLOWED to ensure proper and reliable operation of the device. 5108 FHD F06 Doc. No. 25037-00 2/98 F-1 12 CAT28F020 Abort/Reset POWER SUPPLY DECOUPLING An Abort/Reset command is available to allow the user to safely abort an erase or program sequence. Two consecutive program cycles with FFH on the data bus will abort an erase or a program operation. The abort/ reset operation can interrupt at any time in a program or erase operation and the device is reset to the Read Mode. To reduce the effect of transient power supply voltage spikes, it is good practice to use a 0.1µF ceramic capacitor between VCC and VSS and VPP and VSS. These high-frequency capacitors should be placed as close as possible to the device for optimum decoupling. POWER UP/DOWN PROTECTION The CAT28F020 offers protection against inadvertent programming during VPP and VCC power transitions. When powering up the device there is no power-on sequencing necessary. In other words, VPP and VCC may power up in any order. Additionally VPP may be hardwired to VPPH independent of the state of VCC and any power up/down cycling. The internal command register of the CAT28F020 is reset to the Read Mode on power up. Figure 8. Alternate A.C. Timing for Program Operation PROGRAM VCC POWER-UP SETUP PROGRAM LATCH ADDRESS COMMAND & DATA VERIFY & STANDBY PROGRAMMING COMMAND PROGRAM VCC POWER-DOWN/ VERIFICATION STANDBY ADDRESSES tWC tWC tAVEL tRC tELAX WE (W) tWLEL tEHWH tWLEL tEHWH tEHWH tEHQZ tWLEL OE (G) tEHEH tGHEL tEHGL tDF tEHEL CE (E) tDVEH HIGH-Z DATA (I/O) tEHDX tELEH tDVEH DATA IN = 40H tOE tEHDX tOLZ tELEH tEHDX tDVEH tOH DATA IN = C0H DATA IN tLZ tCE VALID DATA OUT VCC 5.0V 0V tVPEL VPP VPPH VPPL 28F020 F09 13 Doc. No. 25037-00 2/98 F-1 CAT28F020 ALTERNATE CE-CONTROLLED WRITES JEDEC Standard Symbol Symbol 28F020-70 Parameter tAVAV tWC Write Cycle Time tAVEL tAS tELAX Min. Max. 28F020-90 Min. Max. 28F020-12 Min. Max. Unit 70 90 120 ns Address Setup Time 0 0 0 ns tAH Address Hold Time 40 40 40 ns tDVEH tDS Data Setup Time 40 40 40 ns tEHDX tDH Data Hold Time 10 10 10 ns tEHGL — Write Recovery Time Before Read 6 6 6 µs tGHEL — Read Recovery Time Before Write 0 0 0 µs tWLEL tWS WE Setup Time Before CE 0 0 0 ns tEHWH — WE Hold Time After CE 0 0 0 ns tELEH tCP Write Pulse Width 40 40 40 ns tEHEL tCPH Write Pulse Width High 20 20 20 ns tVPEL — VPP Setup Time to CE Low 100 100 100 ns ORDERING INFORMATION Prefix Device # CAT 28F020 Product Number Optional Company ID Suffix N I Temperature Range Blank = Commercial (0˚C to +70˚C) I = Industrial (-40˚C to +85˚C) A = Automotive (-40˚C to +105˚C)* Package N: PLCC P: PDIP T: TSOP (8mmx20mm) TR: TSOP (Reverse Pinout) T -12 Tape & Reel T: 500/Reel Speed 70: 70ns 90: 90ns 12: 120ns 28F020 F12 * -40˚ to +125˚ is available upon request. Note: (1) The device used in the above example is a CAT28F020NI-12T (PLCC, Industrial Temperature, 120 ns access time, Tape & Reel). Doc. No. 25037-00 2/98 F-1 14