Specifications

©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
51
according to host power supply capability.
For SDIO Combo Cards, refer to SDIO specification to set the total card power consumable.
The Power Limit is defined in accordance with the Mechanical Addenda that define thermal
requirements as a function of total card power consumption.
This Function Group is used for any bus mode including UHS-I and UHS-II modes. The default
value of the Power Limit is 0.72W (minimum setting). In Legacy SD and UHS-I cards that have only
VDD1 and not VDD2, this translates to 200mA at 3.6V.
In UHS-I mode, after selecting one of SDR50, SDR104 or DDR50 mode by Function Group 1, host
needs to change the Power Limit to enable the card to operate in higher performance. In UHS-II
mode, the host needs to change the Power Limit after finishing initialization to enable the card to
operate in higher performance. Total card power is the sum of VDD1 and VDD2 power
consumption.
In the other cases which may consume power by some function operations, such functions should
have a function enable method (it will be defined in each Function Specification). After setting
Power Limit, functions should be enabled by the function initialization. In case a function is not
provided with enough power, it will fail initialization and the function is disabled by the card. If a
function does not have a function enable method, the function shall work in 0.72W.
Power restriction described in Table 3-6, Table 3-9.
Function 0-F
F0
F1
F2
F3
F4
F5-FE
FF
Non UHS Mode
1
X
X
X
X
0 ..... 0
1
UHS Mode
1
1
1
1
1
0 ..... 0
1
Note 1: Same values are assigned to all X's: either 0 or 1.
Note 2: For Card compliant to Ver3.0x, all X are equal to 0 in Non UHS Mode and
the support bit for F4 is set to 0 in UHS Mode.
For example, in UHS-I card, when the maximum power of a card is 1.08W (300mA at 3.6V on VDD1),
the card operates at up to 0.72W (200mA at 3.6V on VDD1) when the Current Limit is set to 0.72W and
up to 1.08W when Power Limit is set to 1.44W, 1.80W (and when Function 3 is selected).
Function Group 4
Power Limit
Max. Allowed Power
(VDD1 and VDD2)
Max. Current of
VDD1
Max. Current of
VDD2
Function 0
0.72W
200mA
200mA
Function 1
1.44W
400mA
200mA
Function 2
2.16W
600mA
Note 6
Function 3
2.88W
800mA
Note 6
Function 4
1.80W
400mA
200mA
Note 1: Max. Allowed Power is defined as total of VDD1 and VDD2 power per card at the maximum
voltage: 3.6V for VDD1 and 1.95V for VDD2.
Note 2: UHS-I Card is up to 1.44W even if one of Function 2, 3 or 4 is selected. 1.80W is defined for
UHS-II mode.
Note 3: Function 2 and 3 cannot be used in UHS-II mode.
Note 4: UHS Host should support power supply capability of 400mA for VDD1 and 200mA for VDD2.
VDD1 only Host should set to Function 0 or 1.
Note 5: Host needs to support VDD2 to use UHS-II or NFC supported cards.
Note 6: Max. Current of VDD2 for embedded device will be provided by device vendor.
Table 4-12 : Power Limit and Current Limit of VDD1 and VDD2