THGAMRG7T13BAIL

16

February 14th, 2019

© 2019 Toshiba Memory Corporation

Driver Types Definition

In JEDEC, Driver Type-0 is defined as mandatory for e-MMC HS200&HS400 Device. While four additional Driver

Types (1, 2, 3 and 4) are defined as optional, to allow the support of wider Host loads. The Host may select the most

appropriate Driver Type of the Device (if supported) to achieve optimal signal integrity performance.

Driver Type-0 is targeted for transmission line, based d

istributed system with 50Ω nominal line impedance.

Therefore, it is defined as 50Ω nominal driver. The nominal line impedance should be kept as 50Ω even if Driver Type

would be changed.

For HS200, when tested with CL = 15pF Driver Type-0 shall meet all AC characteristics and HS200 Device output

timing requirements. The test circuit defined in section 10.5.4.3 of JEDEC/MMCA Standard 5.1 is used for testing of

Driver Type-0.

For HS400, when tested with the reference load defined in page 27 HS400 reference load figure, Driver Type-0 or

Driver Type-1 or Driver Type-4 shall meet all AC characteristics and HS400 Device output timing requirements.

Driver

Type

TOSHIBA

e-MMC

Nominal Impedance

(Driver strength)

Approximated driving capability

compared to Type-0

Remark

0

Supported

50 Ω (18mA)

x1

Default Driver Type

1

Supported

33

Ω (27mA)

x1.5

Recommendation at HS400 under the

condition of JEDEC standard

reference load.

2

Supported

66

Ω (14mA)

x0.75

3

Supported

100

Ω (9mA)

x0.5

4

Supported

40

Ω (23mA)

x1.2

Recommendation at HS400 under the

condition of JEDEC standard

reference load.

Note: Nominal impedance is defined by I-V characteristics of output driver at 0.9V when VCCQ = 1.8V.

*

The most suitable setting for user’s operating environment should be selected.

At HS400, Toshiba Memory recommends Driver Type-1 and Type-4. This is because they meet all AC

characteristics and Device output timing requirements under the condition of JEDEC standard reference load.