HN27C256AG Series
32768-word ×8-bit UV Erasable and Programmable ROM
This Hitachi HN27C256AG is a 256-kbit
ultraviolet erasable and electrically programmable
ROM, featuring high speed and low power
dissipation.
Fabricated on advanced fine process and high
speed circuitry technique, the HN27C256AG
makes high speed access time possible for 16 bit
microprocessors such as the 8086 and 68000. And
low power dissipation in active and standby modes
matches our CMOS 256-kbit EPROM.
In programming operation, the HN27C256AG
realizes faster programming times than our
conventional 256-kbit EPROM by Hitachi’s Fast
High-Reliability Programming Algorithm.
Pin arrangement, pin configuration and
programming voltage are compatible with our 256-
kbit EPROM series, therefore existing
programmers can be used with the HN27C256AG.
Features
High speed
Access time: 100/120/150 ns (max)
Low power dissipation
Active mode: 25 mW (typ) (f = 1 MHz)
Standby mode: 5 µW (typ)
High reliability and fast programming
Programming voltage: +12.5 V DC
Fast High-Reliability Programming Algorithm
available
Device identifier mode
Manufacturer code and device code
Ordering Information
Type No. Access time Package
—————————————————————
HN27C256AG-10 100 ns 600-mil 28-pin
——————————————— cerdip
HN27C256AG-12 120 ns (DG-28)
———————————————
HN27C256AG-15 150 ns
—————————————————————
Pin Arrangement
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VPP
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
VSS
VCC
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
(Top View)
1
2
HN27C256AG Series HN27C256AG Series
Block Diagram
512 × 512
Memory Matrix
Y-Gating
Y-Decoder
A0 – A3
A10, A11
: High Threshold Inverter
H
X-Decoder
Input Data
Control
A4 – A9
A12 – A14
Address
I/O0
I/O7
CE
OE
VCC
VPP
VSS
H
Pin Description
Pin name Function
—————————————————————
A0 – A14 Address
—————————————————————
I/O0 – I/O7 Input/output
—————————————————————
CE Chip enable
—————————————————————
OE Output enable
—————————————————————
Pin name Function
—————————————————————
VCC Power supply
—————————————————————
VPP Programming power supply
—————————————————————
VSS Ground
—————————————————————
3
HN27C256AG Series HN27C256AG Series
Mode Selection
CE OE A9 VPP VCC I/O
————————————————————————————————————
Mode (20) (22) (24) (1) (28) (11 – 13, 15 – 19)
———————————————————————————————————————————
Read VIL VIL VCC VCC Dout
———————————————————————————————————————————
Output disable VIL VIH VCC VCC High-Z
———————————————————————————————————————————
Standby VIH ✕✕V
CC VCC High-Z
———————————————————————————————————————————
Program VIL VIH VPP VCC Din
———————————————————————————————————————————
Program verify VIH VIL VPP VCC Dout
———————————————————————————————————————————
Optional verify VIL VIL VPP VCC Dout
———————————————————————————————————————————
Program inhibit VIH VIH VPP VCC High-Z
———————————————————————————————————————————
Identifier VIL VIL VH*2 VCC VCC Code
———————————————————————————————————————————
Notes: 1. : Don’t care.
2. VH: 12.0 V ± 0.5 V.
Absolute Maximum Ratings
Parameter Symbol Value Unit
———————————————————————————————————————————
All input and output voltage*1 Vin, Vout –0.6*2 to +7.0 V
———————————————————————————————————————————
A9 input voltage*1 VID –0.6*2 to +13.5 V
———————————————————————————————————————————
VPP voltage*1 VPP –0.6 to +13.5 V
———————————————————————————————————————————
VCC voltage*1 VCC –0.6 to +7.0 V
———————————————————————————————————————————
Operating temperature range Topr 0 to +70 °C
———————————————————————————————————————————
Storage temperature range Tstg –65 to +125 °C
———————————————————————————————————————————
Storage temperature range under bias Tbias –10 to +80 °C
———————————————————————————————————————————
Notes: 1. Relative to VSS.
2. Vin, Vout, VID min = –1.0 V for pulse width 50 ns.
4
HN27C256AG Series HN27C256AG Series
Capacitance (Ta = 25°C, f = 1 MHz)
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Input capacitance Cin 4 8 pF Vin = 0 V
———————————————————————————————————————————
Output capacitance Cout 8 12 pF Vout = 0 V
———————————————————————————————————————————
Read Operation
DC Characteristics (Ta = 0 to +70°C, VCC = 5 V ± 10%, VPP = VCC)
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Input leakage current ILI 2 µA Vin = 0 V to VCC
———————————————————————————————————————————
Output leakage current ILO 2 µA Vout = 0 V to VCC
———————————————————————————————————————————
VPP current IPP1 1 20 µA VPP = 5.5 V
———————————————————————————————————————————
Standby VCC current ISB1 ——1 mACE = VIH
————————————————————————————————
ISB2 1 20 µA CE = VCC ± 0.3 V
———————————————————————————————————————————
Operating VCC current ICC1 ——30 mACE = VIL, Iout = 0 mA
————————————————————————————————
ICC2 30 mA f = 10 MHz, Iout = 0 mA
————————————————————————————————
ICC3 5 15 mA f = 1 MHz, Iout = 0 mA
———————————————————————————————————————————
Input low voltage*3 VIL –0.3*1 0.8 V
———————————————————————————————————————————
Input high voltage*3 VIH 2.2 VCC + 1.0*2 V
———————————————————————————————————————————
Output low voltage VOL 0.45 V IOL = 2.1 mA
———————————————————————————————————————————
Output high voltage VOH1 2.4 V IOH = –1.0 mA
————————————————————————————————
VOH2 VCC – 0.7 V IOH = –100 µA
———————————————————————————————————————————
Notes: 1. VIL min = –1.0 V for pulse width 50 ns.
2. VIH max = VCC + 1.5 V for pulse width 20 ns.
If VIH is over the specified maximum value, read operation cannot be guaranteed.
3. Only defined for DC function test. VIL max = 0.45 V, VIH min = 2.4 V for AC function test.
AC Characteristics (Ta = 0 to +70°C, VCC = 5 V ± 10%, VPP = VCC)
Test Conditions
Input pulse levels: 0.45 V to 2.4 V
Input rise and fall times: 10 ns
Output load: 1TTL gate + 100 pF
Reference levels for measuring timing: Inputs; 0.8 V and 2.0 V
Outputs; 0.8 V and 2.0 V
HN27C256AG-10 HN27C256AG-12 HN27C256AG-15
Parameter Symbol Min Max Min Max Min Max Unit Test conditions
———————————————————————————————————————————
Address to output delay tACC 100 120 150 ns
CE
=
OE
= VIL
———————————————————————————————————————————
CE
to output delay tCE 100 120 150 ns
OE
= VIL
———————————————————————————————————————————
OE
to output delay tOE —60—60—70ns
CE
= VIL
———————————————————————————————————————————
OE
high to output float tDF 035040050ns
CE
= VIL
———————————————————————————————————————————
Address to output hold tOH 5—5—5—ns
CE
=
OE
= VIL
———————————————————————————————————————————
Note: tDF is defined as the time at which the output achieves the open circuit condition and data is no
longer driven.
Read Timing Waveform
tACC
Address 
CE
Data Out
OE
Standby Mode Active Mode Standby Mode
Data Out Valid
tOE tDF
tOH
tCE
5
HN27C256AG Series HN27C256AG Series
START
SET PROG./VERIFY MODE
VPP = 12.5 ± 0.5 V, VCC = 6.0 ± 0.25 V
Address = 0
n = 0
n + 1 n
Program tPW = 0.2 ms ± 5%
VERIFY
GO
NOGO
NO
NO
YES
NOGO
YES
GO
Program tOPW = 0.2n ms
LAST
Address?
READ
All Address
END FAIL
n = 25
SET READ MODE
VCC = 5.0 V ± 0.5 V, VPP = VCC
Address + 1 Address
6
HN27C256AG Series HN27C256AG Series
Fast High-Reliability Programming
This device can be applied the Fast High-
Reliability Programming Algorithm shown in
following flowchart. This algorithm offers both
faster programming time and high reliability data
retension. A theoretical programming time (except
brank checking and verifying time) is one-tenth of
conventional high performance programming
algorithm’s. Regarding the model and software
version of the programmers available this
algorithm, please contact programmer maker.
DC Characteristics (Ta = 25°C ± 5°C, VCC = 6 V ± 0.25 V, VPP = 12.5 V ± 0.5 V)
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Input leakage current ILI 2 µA Vin = 0 V to VCC
———————————————————————————————————————————
VPP supply current IPP ——30 mACE = VIL
———————————————————————————————————————————
Operating VCC current ICC ——30 mA
———————————————————————————————————————————
Input low level VIL –0.1*5 0.8 V
———————————————————————————————————————————
Input high level VIH 2.2 VCC + 0.5*6 V
———————————————————————————————————————————
Output low voltage VOL 0.45 V IOL = 2.1 mA
during verify
———————————————————————————————————————————
Output high voltage VOH 2.4 V IOH = –400 µA
during verify
———————————————————————————————————————————
Notes: 1. VCC must be applied simultaneously or before VPP and removed simultaneously or after VPP.
2. VPP must not exceed 13.5 V including overshoot.
3. An influence may be had upon device reliability if the device is installed or removed while VPP =
12. 5V.
4. Do not alter VPP either VIL to 12.5 V or 12.5 V or 12.5 V to VIL when CE = Low.
5. VIL min = –0.6 V for pulse width 20 ns.
6. If VIH is over the specified maximum value, programming operation cannot be guaranteed.
7
HN27C256AG Series HN27C256AG Series
AC Characteristics (Ta = 25°C ± 5°C, VCC = 6 V ± 0.25 V, VPP = 12.5 V ± 0.5 V)
Test Conditions
Input pulse levels: 0.45 V to 2.4 V
Input rise and fall times: 20 ns
Reference levels for measuring timing: Inputs; 0.8 V and 2.0 V
Outputs; 0.8 V and 2.0 V
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Address setup time tAS 2 ——µs
———————————————————————————————————————————
OE setup time tOES 2 ——µs
———————————————————————————————————————————
Data setup time tDS 2 ——µs
———————————————————————————————————————————
Address hold time tAH 0 ——µs
———————————————————————————————————————————
Data hold time tDH 2 ——µs
———————————————————————————————————————————
VPP setup time tVPS 2 ——µs
———————————————————————————————————————————
VCC setup time tVCS 2 ——µs
———————————————————————————————————————————
CE initial programming tPW 0.19 0.20 0.21 ms
pulse width
———————————————————————————————————————————
CE over programming tOPW*1 0.19 5.25 ms
pulse width
———————————————————————————————————————————
Data valid from OE tOE 0 150 ns
———————————————————————————————————————————
OE to output float delay tDF*2 130 ns
———————————————————————————————————————————
Notes: 1. Refer to the Fast High-Reliability Programming Flowchart for tOPW.
2. tDF is defined as the time at which the output achieves the open circuit condition and data is no
longer driven.
8
HN27C256AG Series HN27C256AG Series
Fast High-Reliability Programming Timing Waveform
Address 
Data
CE tOE
OE
VPP
VCC
tOES
tPW
tVCS
tVPS
tDS tDH tDF
tAH
tAS
Program Program Verify
Data In Stable Data Out Valid
VPP
VCC
VCC+1
VCC
9
HN27C256AG Series HN27C256AG Series
START
SET PROG./VERIFY MODE
VPP = 12.5 ± 0.5 V, VCC = 6.0 ± 0.25 V
Address = 0
n = 0
n + 1 n
Program tPW = 1.0 ms ± 5%
VERIFY
GO
NOGO
NO
NO
YES
NOGO
YES
GO
Program tOPW = 3n ms
LAST
Address?
READ
All Address
END FAIL
n = 25
SET READ MODE
VCC = 5.0 V ± 0.5 V, VPP = VCC
Address + 1 Address
10
HN27C256AG Series HN27C256AG Series
High Performance Programming
This device can be applied the high performance
programming algorithm shown in following
flowchart. This algorithm is as same as our 256-
kbit EPROM series so existing programmers can
be used with this device. This algorithm allows to
obtain faster programming time without any
voltage stress to the device nor deterioration in
reliability of programmed data.
DC Characteristics (Ta = 25°C ± 5°C, VCC = 6 V ± 0.25 V, VPP = 12.5 V ± 0.5 V)
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Input leakage current ILI 2 µA Vin = 0 V to VCC
———————————————————————————————————————————
VPP supply current IPP ——30 mACE = VIL
———————————————————————————————————————————
Operating VCC current ICC ——30 mA
———————————————————————————————————————————
Input low level VIL –0.1*5 0.8 V
———————————————————————————————————————————
Input high level VIH 2.2 VCC + 0.5*6 V
———————————————————————————————————————————
Output low voltage VOL 0.45 V IOL = 2.1 mA
during verify
———————————————————————————————————————————
Output high voltage VOH 2.4 V IOH = –400 µA
during verify
———————————————————————————————————————————
Notes: 1. VCC must be applied simultaneously or before VPP and removed simultaneously or after VPP.
2. VPP must not exceed 13.5 V including overshoot.
3. An influence may be had upon device reliability if the device is installed or removed while VPP =
12. 5V.
4. Do not alter VPP either VIL to 12.5 V or 12.5 V or 12.5 V to VIL when CE = Low.
5. VIL min = –0.6 V for pulse width 20 ns.
6. If VIH is over the specified maximum value, programming operation cannot be guaranteed.
11
HN27C256AG Series HN27C256AG Series
AC Characteristics (Ta = 25°C ± 5°C, VCC = 6 V ± 0.25 V, VPP = 12.5 V ± 0.5 V)
Test Conditions
Input pulse levels: 0.45 V to 2.4 V
Input rise and fall times: 20 ns
Reference levels for measuring timing: Inputs; 0.8 V and 2.0 V
Outputs; 0.8 V and 2.0 V
Parameter Symbol Min Typ Max Unit Test conditions
———————————————————————————————————————————
Address setup time tAS 2 ——µs
———————————————————————————————————————————
OE setup time tOES 2 ——µs
———————————————————————————————————————————
Data setup time tDS 2 ——µs
———————————————————————————————————————————
Address hold time tAH 0 ——µs
———————————————————————————————————————————
Data hold time tDH 2 ——µs
———————————————————————————————————————————
VPP setup time tVPS 2 ——µs
———————————————————————————————————————————
VCC setup time tVCS 2 ——µs
———————————————————————————————————————————
CE initial programming tPW 0.95 1.0 1.05 ms
pulse width
———————————————————————————————————————————
CE over programming tOPW*1 2.85 78.75 ms
pulse width
———————————————————————————————————————————
Data valid from OE tOE 0 150 ns
———————————————————————————————————————————
OE to output float delay tDF*2 130 ns
———————————————————————————————————————————
Notes: 1. Refer to the high performance programming flowchart for tOPW.
2. tDF is defined as the time at which the output achieves the open circuit condition and data is no
longer driven.
12
HN27C256AG Series HN27C256AG Series
High Performance Programming Timing Waveform
Address 
Data
CE tOE
OE
VPP
VCC
tOES
tPW
tVCS
tVPS
tDS tDH tDF
tAH
tAS
Program Program Verify
Data In Stable Data Out Valid
VPP
VCC
VCC + 1
VCC
13
HN27C256AG Series HN27C256AG Series
Erase
Erasure of HN27C256AG is performed by
exposure to ultraviolet light of 2537 Å and all the
output data are changed to “1” after this erasure
procedure. The minimum integrated dose (i.e. UV
intensity ×exposure time) for erasure is 15
W•sec/cm2.
Mode Description
Device Identifier Mode
Programming condition of EPROM is various
according to EPROM manufacturers and device
types. It may cause miss operation. To
countermeasure it, some EPROMs provide maker
identifier code. Users can write EPROM by
reading out write condition coded before shipped.
Some commercial programmers can set write
condition by recognizing this code. This function
enables effective program. Regarding commercial
programmers that can recognize this device’s
identifier code, please contact programmer maker.
14
HN27C256AG Series HN27C256AG Series
HN27C256AG Series Identifier Code
A0 I/O7 I/O6 I/O5 I/O4 I/O3 I/O2 I/O1 I/O0 Hex
———————————————————————————————
Identifier (10) (19) (18) (17) (16) (15) (13) (12) (11) data
———————————————————————————————————————————
Manufacturer code VIL 0000011107
———————————————————————————————————————————
Device code VIH 0011000131
———————————————————————————————————————————
Notes: 1. A9 = 12.0 V ± 0.5 V.
2. A1 – A8, A10 – A14, CE, OE = VIL.