www.ti.com

POWER STATES

DISCHARGE FETs

TPS2231

TPS2236

SLVS536B – JULY 2004 – REVISED JANUARY 2005

If AUXIN is not present, then all input-to-output power switches are kept off (OFF mode).

If AUXIN is present and SHDN is asserted (logic low), then all input-to-output power switches are kept off and the

output discharge FETs are turned on (Shutdown mode). If SHDN is asserted and then de-asserted, the state on

the outputs is restored to the state prior to SHDN assertion.

If 3.3VIN, AUXIN and 1.5VIN are present at the input of the power switch and no card is inserted, then all

input-to-output power switches are kept off and the output discharge FETs are turned on (No Card mode).

If 3.3VIN, AUXIN and 1.5VIN are present at the input of the power switch prior to a card being inserted, then all

input-to-output power switches are turned on once a card-present signal (CPUSB and/or CPPE) is detected

(Card Inserted mode).

If a card is present and all output voltages are being applied, then the STBY is asserted (logic low); the AUXOUT

voltage is provided to the card, and the 3.3VOUT and 1.5VOUT switches are turned off (Standby mode).

If a card is present and all output voltages are being applied, then the 1.5VIN, or 3.3VIN is removed from the

input of the power switch; the AUXOUT voltage is provided to the card and the 3.3VOUT and 1.5VOUT switches

are turned off (Standby mode).

If prior to the insertion of a card, the AUXIN is available at the input of the power switch and 3.3VIN and/or

1.5VIN are not, or if STBY is asserted (logic low), then no power is made available to the card (OFF mode). If

1.5VIN and 3.3VIN are made available at the input of the power switch after the card is inserted and STBY is not

asserted, all the output voltages are made available to the card (Card Inserted mode).

The discharge FETs on the outputs are activated whenever the device detects that a card is not present (No

Card mode). Activation occurs after the input-to-output power switches are turned off (break before make). The

discharge FETs de-activate if either of the card-present lines go active low, unless the SHDN pin is asserted.

The discharge FETs are also activated whenever the SHDN input is asserted and stay asserted until SHDN is

de-asserted.

12