Sanyo LC35256FT-70U Specifications

Ordering number : ENN*6302

CMOS IC

LC35256FM, FT-55U/70U

256K (32768 words × 8 bits) SRAM

Control Pins: OE and CE

Preliminary

Overview

The LC35256FM and LC35256FT are asynchronous silicon-gate CMOS SRAMs with a 32K-word by 8-bit structure. These are full-CMOS devices with 6 transistors per memory cell, and feature low-voltage operation, a low operating current drain, and an ultralow standby current.

Control inputs include OE for fast memory access and CE (chip enable) for power saving and device selection. This makes these devices optimal for systems that require low power or battery backup, and makes memory expansion easy. The ultralow standby current allows these devices to be used with capacitor backup as well.

Features

•Supply voltage range: 4.5 to 5.5 V

•Access time at 5 V operation: LC35256FM, FT-55U: 55 ns (maximum) LC35256FM, FT-70U: 70 ns (maximum)

•Standby current: 3.0 µA (Ta ≤ 70°C)

5.0µA (Ta ≤ 85°C)

•Operating temperature: –40 to +85°C

•Data retention voltage: 2.0 to 5.5 V

•All I/O levels: TTL compatible

•Input/output shared function pins, 3-state output pins

•No clock required

•Package

28-pin SOP (450 mil) plastic package: LC35256FM 28-pin TSOP (8 × 13.4 mm) plastic package: LC35256FT

Package Dimensions

unit: mm

3187A-SOP28D

[LC35256FM]

28	15		0.15
	9.8	8.4	11.8
			1.0
1	14
18.0
	0.1 2.3
0.4	1.27

SANYO: SOP28D

unit: mm

3221-TSOP28 (Type I)

[LC35256FT]

21		8
			11.8	13.4
				0.5
22	28 1	7	1.27max
	0.55	0.2		0.125
	8.1
			0.08

SANYO: TSOP28 (Type I)

Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft’s control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO products described or contained herein.

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

52600RM (OT) No. 6302-1/7

LC35256FM, FT-55U/70U

Pin Assignment (Top view)

			TSOP28										SOP28D
OE	22			21					A10		A14					VCC
												1		28
A11			23	20					CE
A9			24	19					I/O8		A12	2		27		WE
A8			25	18					I/O7		A7					A13
A13			26	17					I/O6			3		26
WE			27	16					I/O5		A6					A8
VCC			28	15					I/O4			4		25
A14			1	14					GND		A5	5		24		A9
A12			2	13					I/O3
A7			3	12					I/O2		A4	6		23		A11
A6			4	11					I/O1
A5			5	10					A0		A3	7		22			OE
A4			6	9					A1
A3			7	8					A2		A2	8		21		A10
											A1
			LC35256FT									9		20			CE
											A0					I/O8
												10		19
											I/O1					I/O7
												11		18
											I/O2					I/O6
												12		17
											I/O3					I/O5
												13		16
											GND					I/O4
												14		15

LC35256FM

Block Diagram

A6
A7
A8	buffer
A9
A10	Address
A11
A12
A13
A14
I/O1
I/O8
CE
WE
OE

Row decoder

Input data buffer

Input data control circuit

VCC

Memory cell array

512 × 512

GND

Column I/O	Output
circuit	data
	buffer
Column decoder

Address buffer

A0 A1 A2 A3 A4 A5

No. 6302-2/7

LC35256FM, FT-55U/70U

Pin Functions

A0 to A14					Address input
					Read/write control input
	WE
					Output enable input
		OE
					Chip enable input
	CE
I/O1 to I/O8					Data I/O
VCC, GND					Power supply, ground

Function Table

Mode		CE			OE			WE		I/O	Supply current
Read cycle		L			L			H		Data output	ICCA
Write cycle		L			X			L		Data input	ICCA
Output disable		L			H			H		High impedance	ICCA
Unselected		H			X			X		High impedance	ICCS

Specifications

Absolute Maximum Ratings

Parameter	Symbol	Conditions	Ratings	Unit
Maximum supply voltage	VCC max		7.0	V
Input pin voltage	VIN		–0.3* to VCC + 0.3	V
I/O pin voltage	VI/O		–0.3 to VCC + 0.3	V
Operating temperature	Topr		–40 to +85	°C
Storage temperature	Tstg		–55 to +125	°C

Note: * The minimum value is –3.0 V for pulse widths under 30 ns.

I/O Capacitances at Ta = 25°C, f = 1 MHz

	Parameter	Symbol	Conditions		Ratings		Unit
				min	typ	max
	I/O pin capacitance	CI/O	VI/O = 0 V		6	10	pF
	Input pin capacitance	CI	VIN = 0 V		6	10	pF

Note: All units are not tested; only samples are tested.

DC Allowable Operating Ranges at Ta = –40 to +85°C, VCC = 4.5 to 5.5 V

	Parameter	Symbol	Conditions		Ratings		Unit
				min	typ	max
	Supply voltage	VCC		4.5	5.0	5.5	V
	Input voltage	VIH		2.2		VCC + 0.3	V
		VIL		–0.3*		+0.8	V

Note: * The minimum value is –3.0 V for pulse widths under 30 ns.

No. 6302-3/7