MR256DL08BMA45 - EVERSPIN TECHNOLOGIES

MR256DL08B

Dual Supply 32K x 8 MRAM

FEATURES

• 3.3 Volt VDD power supply with a range of 2.7V to 3.6V

• I/O Voltage range supports wide +1.65 to +3.6 Volt interfaces

• Fast 45 ns read/write cycle

• SRAM compatible timing

• Unlimited read & write endurance

• Data always non-volatile for >20-years at temperature

• All products meet MSL-3 moisture sensitivity level

• RoHS-compliant small footprint BGA package

INTRODUCTION

The MR256DL08B is a 262,144-bit magnetoresistive random access memory (MRAM) device organized as

32,768 words of 8 bits. It supports I/O voltages from +1.65 to +3.6 volts. The MR256DL08B oers SRAM

compatible 45ns read/write timing with unlimited endurance. Data is always non-volatile for greater than

20-years. Data is automatically protected on power loss by low-voltage inhibit circuitry to prevent writes

with voltage out of specication. The MR256DL08B is the ideal memory solution for applications that

must permanently store and retrieve critical data and programs quickly.

The MR256DL08B is available in small footprint 8 mm x 8 mm, 48-pin ball grid array (BGA) package with

0.75 mm ball centers.

The MR256DL08B provides highly reliable data storage over a wide range of temperatures. The product is

oered with commercial temperature (0 to +70 °C).

RoHS

CONTENTS

1. DEVICE PIN ASSIGNMENT......................................................................... 2

2. ELECTRICAL SPECIFICATIONS................................................................. 4

3. TIMING SPECIFICATIONS.......................................................................... 8

4. ORDERING INFORMATION....................................................................... 13

5. MECHANICAL DRAWING.......................................................................... 14

6. REVISION HISTORY...................................................................................... 15

How to Reach Us.......................................................................................... 15

BENEFITS

• One memory replaces FLASH, SRAM, EEPROM and BBSRAM in systems

for simpler, more ecient designs

• Improves reliability by replacing battery-backed SRAM

1. DEVICE PIN ASSIGNMENT

Figure 1.1 Block Diagram

Table 1.1 Pin Functions

Signal Name Function

A Address Input

E Chip Enable

W Write Enable

G Output Enable

DQ Data I/O

VDD Power Supply

VDDQ I/O Power Supply

VSS Ground

DC Do Not Connect

NC No Connection, Ball D3, H1, H6, G2 Reserved for Future Expansion

MR256DL08B

CHIP

ENABLE

BUFFER

OUTPUT

ENABLE

BUFFER

ADDRESS

BUFFER

WRITE

ENABLE

BUFFER

OUTPUT ENABLE

32K x 8 BIT

MEMORY

ARRAY

ROW

DECODER COLUMN

DECODER

SENSE

AMPS

OUTPUT

BUFFER

WRITE

DRIVER

FINAL

WRITE

DRIVERS

WRITE ENABLE

A[14:0]

DQ[7:0]

123456

G A A A A

AAEB

DQ AA

DQ C

DDQ

A A

DQ F

DCDC

Figure 1.2 Pin Diagrams for Available Packages (Top View)

48 Pin FBGA

Table 1.2 Operating Modes

E1G1W1Mode VDD Current DQ[7:0]2

H X X Not selected ISB1, ISB2 Hi-Z

L H H Output disabled IDDR Hi-Z

L L H Byte Read IDDR DOut

L X L Byte Write IDDW Din

1 H = high, L = low, X = don’t care

2 Hi-Z = high impedance

DEVICE PIN ASSIGNMENT MR256DL08B

2. ELECTRICAL SPECIFICATIONS

Absolute Maximum Ratings

This device contains circuitry to protect the inputs against damage caused by high static voltages or

electric elds; however, it is advised that normal precautions be taken to avoid application of any

voltage greater than maximum rated voltages to these high-impedance (Hi-Z) circuits.

The device also contains protection against external magnetic elds. Precautions should be taken

to avoid application of any magnetic eld more intense than the maximum eld intensity specied

in the maximum ratings.

Parameter Symbol Value Unit

Core Supply voltage2VDD -0.5 to 4.0 V

I/O Power Supply voltage2VDDQ -0.5 to 4.0 V

Voltage on any pin2VIN

-0.5 to +4.0 or

VDDQ + 0.5

whichever is less

Output current per pin IOUT ±20 mA

Package power dissipation 3PD0.600 W

Temperature under bias TBIAS -10 to 85 °C

Storage Temperature Tstg -55 to 150 °C

Lead temperature during solder (3 minute max) TLead 260 °C

Maximum magnetic eld during write Hmax_write 2000 A/m

Maximum magnetic eld during read or standby Hmax_read 8000 A/m

1 Permanent device damage may occur if absolute maximum ratings are exceeded. Functional opera-

tion should be restricted to recommended operating conditions. Exposure to excessive voltages or

magnetic elds could aect device reliability.

2 All voltages are referenced to VSS.

3 Power dissipation capability depends on package characteristics and use environment.

Table 2.1 Absolute Maximum Ratings1

MR256DL08B

Parameter Symbol Min Typical Max Unit

Core Power supply voltage VDD 2.7 13.3 3.6 V

I/O Power supply voltage VDDQ 1.65 1- 3.6 V

Write inhibit voltage VDD VWIDD 2.3 2.5 2.7 1V

Write inhibit voltage VDDQ VWIDDQ 1.2 1.4 1.65 1V

Input high voltage (VDDQ=1.65-2.2V) VIH 1.4 - VDDQ + 0.2 2 V

Input high voltage (VDDQ=2.2-2.7V) VIH 1.8 - VDDQ + 0.2 2 V

Input high voltage (VDDQ=2.7-3.6V) VIH 2.2 - VDDQ + 0.2 2 V

Input low voltage (VDDQ=1.65-2.2V) VIL -0.2 3- 0.4 V

Input low voltage (VDDQ=2.2-2.7V) VIL -0.2 3- 0.6 V

Input low voltage (VDDQ=2.7-3.6V) VIL -0.2 3- 0.8 V

Access Time TA0 70 °C

Notes:

1. VDDQ≤VDD. Write inhibit occurs when either VDD or VDDQ drops below its write inhibit voltage. There is a 2 ms startup time once

VDD exceeds VDD(min). See Power Up and Power Down Sequencing.

2. VIH(max) = VDDQ + 0.2 V DC ; VIH(max) = VDDQ + 0.5 V AC (pulse width ≤ 20 ns) for I ≤ 20.0 mA.

3. VIL(min) = -0.2 V DC ; VIL(min) = -2.0 V AC (pulse width ≤ 20 ns) for I ≤ 20.0 mA.

Table 2.2 Operating Conditions

MR256DL08B

Electrical Specications

Power Up and Power Down Sequencing

The MRAM is protected from write operations whenever VDD is less than VWIDD or VDDQ is less than VWIDDQ. As

soon as VDD exceeds VDD(min) and VDDQ exceeds VDDQ(min), there is a startup time of 2 ms before read or write

operations can start. This time allows memory power supplies to stabilize.

The E and W control signals should track VDD on power up to VDD- 0.2 V or VIH (whichever is lower) and remain

high for the startup time. In most systems, this means that these signals should be pulled up with a resistor

so that signal remains high if the driving signal is Hi-Z during power up.

Any logic that drives E and W should hold the signals high with a power-on reset signal for longer than the

startup time.

During power loss or brownout where either VDD goes below VWIDD or VDDQ goes below VWIDDQ, writes are pro-

tected and a startup time must be observed when power returns above VDD(min) and / or VDDQ.

Figure 2.1 Power Up and Power Down Sequencing

MR256DL08B

Electrical Specications

BROWNOUT or POWER LOSS

NORMAL

OPERATION

VDD / VDDQ

READ/WRITE

INHIBITED

VWIDD

VWIDDQ

2 ms

READ/WRITE

INHIBITED

VIH

STARTUP

NORMAL

OPERATION

2 ms

RECOVER

VIH

Parameter Symbol Typical Max Unit

AC active supply current - read modes1

(IOUT= 0 mA, VDD= max) IDDR 25 30 mA

AC active supply current - write modes1

(VDD= max) IDDW 55 65 mA

AC active operating current

(VDDQ = VIH= 3.6V, VIL= 0V)

input transitions <2ns, no output load

IDDQ 0.50 2 mA

AC standby current

(VDD= max, E = VIH)

no other restrictions on other inputs

ISB1 6 8 mA

CMOS standby current

(E ≥ VDD - 0.2 V and VIn ≤ VSS + 0.2 V or ≥ VDDQ - 0.2 V)

(VDD = max, f = 0 MHz)

ISB2 5 7 mA

1 All active current measurements are measured with one address transition per cycle and at minimum cycle time.

Parameter Symbol Min Typical Max Unit

Input leakage current Ilkg(I) - - ±1 μA

Output leakage current Ilkg(O) - - ±1 μA

Output low voltage (VDDQ=1.65-2.2V@ 0.1mA) VOL - - 0.2 V

Output low voltage (VDDQ=2.2-2.7V@ 0.1mA) VOL - - 0.4 V

Output low voltage (VDDQ=2.7-3.6V@ 2.1 mA) VOL - - 0.4 V

Output high voltage (VDDQ=1.65-2.2V@ - 0.1 mA) VOH 1.4 - - V

Output high voltage (VDDQ=2.2-2.7V@ -0.1 mA) VOH 2 - - V

Output high voltage (VDDQ=2.7-3.6V@ -1.0 mA) VOH 2.4 - - V

Table 2.3 DC Characteristics

Table 2.4 Power Supply Characteristics

MR256DL08B

Electrical Specications

MR256DL08B

3. TIMING SPECIFICATIONS

Table 3.1 Capacitance1

Parameter Symbol Typical Max Unit

Address input capacitance CIn - 6 pF

Control input capacitance CIn - 6 pF

Input/Output capacitance CI/O - 8 pF

1 f = 1.0 MHz, VDDQ=VDDQ(typ), TA = 25 °C, periodically sampled rather than 100% tested.

Table 3.2 AC Measurement Conditions

Figure 3.1 Output Load Test Low and High

Figure 3.2 Output Load Test All Others

Parameter VDDQ=1.8 VDDQ=2.5 VDDQ=3.3 Unit

Logic input timing measurement reference level 0.8 0.8 0.8 V

Logic output timing measurement reference level 0.8 0.8 0.8 V

Logic input pulse levels 0 or 1.8 0 or 2.5 0 or 3.3 V

Output load voltage (VL) for low & high impedance

parameters (Figure 3.1) 0.8 1.2 1.75 V

Output load resistor (R1) for all other timing 13,500 16,600 1,103 Ω

Output load resistor (R2) for all other timing 10,800 15,400 1,554 Ω

Output

RL= 50 Ω

ZD= 50 Ω

Output

30 pF

VDDQ

MR256DL08B

Timing Specications

Parameter Symbol Min Max Unit

Read cycle time tAVAV 45 - ns

Address access time tAVQV - 45 ns

Enable access time2tELQV - 45 ns

Output enable access time tGLQV - 20 ns

Output hold from address change tAXQX 3 - ns

Enable low to output active3tELQX 3 - ns

Output enable low to output active3tGLQX 0 - ns

Enable high to output Hi-Z3tEHQZ 0 15 ns

Output enable high to output Hi-Z3tGHQZ 0 15 ns

1 W is high for read cycle. Power supplies must be properly grounded and decoupled, and bus contention conditions must be

minimized or eliminated during read or write cycles.

2 Addresses valid before or at the same time E goes low.

3 This parameter is sampled and not 100% tested. Transition is measured ±200 mV from the steady-state voltage.

Table 3.3 Read Cycle Timing1

Read Mode

Figure 3.3A Read Cycle 1

Figure 3.3B Read Cycle 2

A (ADDRESS)

Q (DATA OUT)

tAVAV

tAXQX

tAVQV

Previous Data Valid Data Valid

NOTE: Device is continuously selected (E ≤ VIL, G ≤ VIL)

A (ADDRESS)

E (CHIP ENABLE)

G (OUTPUT ENABLE)

Q (DATA OUT)

Data Valid

AVAV

AVQV

ELQV

ELQX

GHQZ

EHQZ

GLQV

GLQX

MR256DL08B

Timing Specications

Table 3.4 Write Cycle Timing 1 (W Controlled)1

Parameter Symbol Min Max Unit

Write cycle time2tAVAV 45 - ns

Address set-up time tAVWL 0 - ns

Address valid to end of write (G high) tAVWH 25 - ns

Address valid to end of write (G low) tAVWH 25 - ns

Write pulse width (G high) tWLWH

tWLEH

20 - ns

Write pulse width (G low) tWLWH

tWLEH

20 - ns

Data valid to end of write tDVWH 15 - ns

Data hold time tWHDX 0 - ns

Write low to data Hi-Z3tWLQZ 0 15 ns

Write high to output active3tWHQX 3 - ns

Write recovery time tWHAX 12 - ns

1 All writes occur during the overlap of E low and W low. Power supplies must be properly grounded and decoupled and bus

contention conditions must be minimized or eliminated during read and write cycles. If G goes low at the same time or after

W goes low, the output will remain in a high impedance state. After W or E has been brought high, the signal must remain in

steady-state high for a minimum of 2 ns. The minimum time between E being asserted low in one cycle to E being asserted

low in a subsequent cycle is the same as the minimum cycle time allowed for the device.

2 All write cycle timings are referenced from the last valid address to the rst transition address.

3 This parameter is sampled and not 100% tested. Transition is measured ±200 mV from the steady-state voltage. At any given

voltage or temperature, tWLQZ(max) < tWHQX(min)

Figure 3.4 Write Cycle Timing 1 (W Controlled)

MR256DL08B

Timing Specications

Table 3.5 Write Cycle Timing 2 (E Controlled)1

Figure 3.5 Write Cycle Timing 2 (E Controlled)

Parameter Symbol Min Max Unit

Write cycle time2tAVAV 45 - ns

Address set-up time tAVEL 0 - ns

Address valid to end of write (G high) tAVEH 25 - ns

Address valid to end of write (G low) tAVEH 25 - ns

Enable to end of write (G high) tELEH

tELWH

20 - ns

Enable to end of write (G low)3tELEH

tELWH

20 - ns

Data valid to end of write tDVEH 15 - ns

Data hold time tEHDX 0 - ns

Write recovery time tEHAX 12 - ns

1 All writes occur during the overlap of E low and W low. Power supplies must be properly grounded and decoupled and bus

contention conditions must be minimized or eliminated during read and write cycles. If G goes low at the same time or after

W goes low, the output will remain in a high impedance state. After W or E has been brought high, the signal must remain in

steady-state high for a minimum of 2 ns. The minimum time between E being asserted low in one cycle to E being asserted

low in a subsequent cycle is the same as the minimum cycle time allowed for the device.

2 All write cycle timings are referenced from the last valid address to the rst transition address.

3 If E goes low at the same time or after W goes low, the output will remain in a high-impedance state. If E goes high at the

same time or before W goes high, the output will remain in a high-impedance state.

A (ADDRESS)

E (CHIP ENABLE)

W (WRITE ENABLE)

Q (DATA OUT)

D (DATA IN)

AVAV

AVEH

EHAX

ELEH

EHDX

DVEH

AVEL

Hi-Z

ELWH

Data Valid

MR256DL08B

Timing Specications

Table 3.6 Write Cycle Timing 3 (Shortened tWHAX, W and E Controlled)1

Table 3.6 Write Cycle Timing 3 (Shortened tWHAX, W and E Controlled)

Parameter Symbol Min Max Unit

Write cycle time2tAVAV 45 - ns

Address set-up time tAVWL 0 - ns

Address valid to end of write (G high) tAVWH 25 - ns

Address valid to end of write (G low) tAVWH 25 - ns

Write pulse width tWLWH

tWLEH

20 - ns

Data valid to end of write tDVWH 15 - ns

Data hold time tWHDX 0 - ns

Enable recovery time tEHAX -2 - ns

Write recovery time3tWHAX 6 - ns

Write to enable recovery time3tWHEL 12 - ns