UCS1002-3 datasheet(34/114 Pages) MICROCHIP

34 / 114 page

UCS1002-3

DS20006852A-page 34

 2023 Microchip Technology Inc. and its subsidiaries

7.2

Thermal Management and Voltage

Protection

7.2.1

THERMAL MANAGEMENT

The UCS1002-3 utilizes two-stage internal thermal

management: Dynamic Thermal Management and

Fixed Thermal Shutdown.

7.2.1.1

Dynamic Thermal Management

For the first stage (active in both current limiting

modes), referred to as Dynamic Thermal Management,

the UCS1002-3 automatically adjusts port power

switch limits and modes to lower power dissipation

when the thermal regulation temperature value is

approached as described below.

If the internal temperature exceeds the TREG value, the

port power switch is opened, the current limit (ILIM) is

lowered by one step and a timer is started (tDC_TEMP).

When this timer expires, the port power switch is closed

and the internal temperature is checked again. If it

remains above the TREG threshold, the UCS81003

repeats this cycle (opens port power switch and

reduces the ILIM setting by one step) until ILIM reaches

its minimum value.

If the UCS1002-3 is operating using Constant Current

Limiting (variable slope) and the ILIM setting is reduced

to its minimum set point and the temperature is still

above TREG, the UCS1002-3 switches to operating

using Trip Current Limiting. This is done by reducing

the IBUS_R2MIN setting to 100 mA and restoring the ILIM

setting to the value immediately below the programmed

setting (for example, if the programmed ILIM is 1.8A,

the value is set to 1.5A). If the temperature continues to

remain above TREG, the UCS1002-3 continues this

cycle (open the port power switch and reduce the ILIM

setting by one step).

If the UCS1002-3 internal temperature drops below

TREG –TREG_HYST, the UCS1002-3 takes action based

on the following:

If the Current Limit mode changed from CC

mode to Trip mode, then a timer is started. When

this timer expires, the UCS1002-3 resets the port

power

switch

operation

its

original

configuration, enabling it to operate using

Constant Current Limiting (variable slope).

If the Current Limit mode did not change from CC

mode to Trip mode, or has started operating in Trip

mode, the UCS1002-3 resets the port power

switch operation to its original configuration.

If the UCS1002-3 is operating using Trip Current

Limiting and the ILIM setting is reduced to its minimum

set point and the temperature is above TREG, the port

power switch is closed and the current limit is held at its

minimum setting until the temperature drops below

TREG –TREG_HYST.

7.2.1.2

Thermal Shutdown

The second-stage thermal management consists of a

hardware

implemented

thermal

shutdown

corresponding to the maximum allowable internal die

temperature (TTSD). If the internal temperature

exceeds this value, the port power switch immediately

turns OFF until the temperature is below the value of

TTSD –TTSD_HYST.

7.3

VBUS Discharge

The UCS1002-3 discharges VBUS through an internal

100

 resistor when at least one of the following

conditions occurs:

• The PWR_EN control is disabled (triggered on the

inactive edge of the PWR_EN control).

• A portable device Removal Detection event is

flagged.

• The VS voltage drops below a specified

threshold (VS_UVLO) that causes the port power

switch to be disabled.

• When commanded into the Sleep power state via

the EM_EN, M1, and M2 controls.

• Before each charger emulation profile is applied

(UCS81003AM and UCS81003AB), unless it is a

power-up condition (UCS1002-3 only).

• Upon recovery from the Error state.

• When commanded via the SMBus (see

Section 10.4 “Configuration Registers”) in the

Active state.

• Any time that the port power switch is activated

after the VBUS bypass switch is ON (that is,

whenever VBUS voltage transitions from being

driven from VDD to being driven from VS, such as

going from Detect to Active power state).

• Any time that the VBUS bypass switch is acti-

vated after the port power switch is ON (that is,

going from Active to Detect power state).

Note 1: If the temperature exceeds the TREG

threshold while operating in the DCE

Cycle mode after a charger emulation pro-

file is accepted, the profile is removed.

The UCS1002-3 does not restart the DCE

Cycle until one of the control inputs

changes state to restart emulation.

2: The UCS1002-3 does not actively

discharge VBUS as a result of the

temperature exceeding TREG; however,

any load current provided by a portable

device or other load causes VBUS to be

discharged when the port power switch is

opened, possibly resulting in an attached

portable device resetting.

UCS1002-3 Datasheet(PDF) 34 Page - Microchip Technology

UCS1002-3 Datasheet(HTML) 34 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL