JAJSHI3C March 2019 – October 2019 TPS23881
PRODUCTION DATA.
COMMAND = 21h with 1 Data Byte, Read/Write
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
POL4_7 | POL4_6 | POL4_5 | POL4_4 | POL4_3 | POL4_2 | POL4_1 | POL4_0 |
R/W-1 | R/W-1 | R/W-1 | R/W-1 | R/W-1 | R/W-1 | R/W-1 | R/W1 |
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset |
Bit | Field | Type | Reset | Description |
---|---|---|---|---|
7–0 | POLn_7- POLn_0 | R/W | 1 | 1-byte defining 2-Pair PCUTminimum threshold.
The equation defining the PCUT is: PCUT = (N × PCSTEP) Where, when assuming 0.200-Ω Rsense resistor is used: PCSTEP = 0.5 W |
SPACE
NOTE
These bits set the minimum threshold for the design. Internally, the typical PCUT threshold is set slightly above this value to ensure that the device does not trip a Pcut fault at or below the set value in this register due to part to part or temperature variation.
For 4-pair wired ports, the 2P Policing values are still applied to the individual channels. See the description for registers 0x2Ah and 0x2Bh for more information on 4-Pair Policing.
The contents of this register is reset to 0xFFh anytime the port is turned off or disabled either due to fault condition or user command
NOTE
Programmed values of less than 2W are not supported. If a value of less than 2W is programmed into these registers, the device will use 2W as the 2-pair Policing value.
SPACE
Power Policing:
The TPS23881 implements a true Power Policing limit, where the device will adjust the policing limit based on both voltage and current variation in order to ensure a reliable power limit.
In Semi Auto and Auto modes, these bits are automatically set during power on based on the assigned class (see tables below). If an alternative value is desired, it needs to be set after the PEn bit is set in 0x10h, or it may also be configured prior to port turn on in combination with the use of the MPOLn bits in register 0x40 (see 2x FOLDBACK SELECTION Register).
Assigned Class | POLn7-0 Settings | Minimum Power |
---|---|---|
Class 1 | 0000 1000 | 4W |
Class 2 | 0000 1110 | 7W |
Class 3 | 0001 1111 | 15.5W |
Class 4 | 0011 1100 | 30W |
Class 5 Dual Signature | 0101 1010 | 45W |
Assigned Class | POLn7-0 Settings | Minimum Power |
---|---|---|
Class 1 | 0000 1000 | 4W(1) |
Class 2 | 0000 1110 | 7W(1) |
Class 3 | 0001 1111 | 15.5W(1) |
Class 4 | 0011 1100 | 30W(1) |
Class 5 | 0100 0000 | 32W(2) |
Class 6 | 0100 1110 | 39W(2) |
Class 7 | 0101 1001 | 44.5W(2) |
Class 8 | 0110 1011 | 53.5W(2) |