TPD4S014 是一款用于 USB 充电器端口保护的单芯片解决方案。该器件为 D+、D- 提供低电容瞬态电压抑制器 (TVS) 静电放电 (ESD) 钳位并为 ID 引脚提供标准电容。该器件在 VBUS 引脚提供直流电压高达 28V 的过压保护 (OVP)。过压锁定功能可确保当 VBUS 线路出现故障情况时,TPD4S014 能够隔离 VBUS 线路,从而避免内部电路受损。VBUS 升至欠压锁定 (UVLO) 阈值后存在 17ms 开机延迟,从而在 nFET 导通前使电压趋于稳定。该功能可去除毛刺脉冲并避免因线路连接过程中出现的任何振铃问题导致意外开关。
器件型号 | 封装 | 封装尺寸(标称值) |
---|---|---|
TPD4S014 | WSON (10) | 2.00mm x 2.00mm |
Changes from F Revision (September 2015) to G Revision
Changes from E Revision (June 2014) to F Revision
Changes from D Revision (April 2014) to E Revision
Changes from C Revision (December 2011) to D Revision
Changes from B Revision (October 2011) to C Revision
Changes from A Revision (June 2011) to B Revision
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
VBUSOUT | 1, 2 | Power Output | Connect to PCB internal PCB plane |
EN | 3 | IO | Enable Active-Low Input. Drive EN low to enable the switch. Drive EN high to disable the switch. |
ACK | 4 | I | Open-Drain Adapter-Voltage Indicator Output. ACK is driven low after the VIN voltage is stable between UVLO and OVLO for 17 ms (typ). Connect a pullup resistor from ACK to the logic I/O voltage of the host system. |
ID | 5 | IO | ESD-protected line |
D– | 6 | IO | ESD-protected line |
D+ | 7 | IO | ESD-protected line |
GND | 8 | Ground | Ground |
VBUS | 9, 10 | USB Input Power | Connector Side of VBUS |
Central PAD | Central PAD | Heat Sink | Electrically disconnected. Use as heat sink. Connect to GND plane via large PCB PAD |
VALUE | UNIT | ||||
---|---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | ±2000 | V | |
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) | ±1000 | ||||
IEC 61000-4-2 Contact Discharge | D+, D–, ID, VBUS pins | ±1500 | |||
IEC 61000-4-2 Air-gap Discharge | D+, D–, ID, VBUS pins | ±1500 |
MIN | NOM | MAX | UNIT | |||
---|---|---|---|---|---|---|
TA | Operating free-air temperature | –40 | 85 | °C | ||
VI | Input voltage | VBUSOUT | –0.1 | 5.5 | V | |
VBUS | –0.1 | 5.5 | ||||
EN | –0.1 | 5.5 | ||||
ACK | –0.1 | 5.5 | ||||
D+, D-, ID, | –0.1 | 5.5 | ||||
IVBUS | VBUS continuous current(1) | VBUSOUT | 2.0 | A | ||
CVBUS | Capacitance on VBUS | VBUS Pin | 10 | µF | ||
CVBUSOUT | Capacitance on VBUSOUT | VBUSOUT Pin | 10 | µF | ||
RACK | Pullup resistor on ACK | ACK Pin | 10 | kΩ |
THERMAL METRIC(1) | TPD4S014 | UNIT | |
---|---|---|---|
DSQ (WSON) | |||
8 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 70.3 | °C/W |
RθJCtop | Junction-to-case (top) thermal resistance | 46.3 | °C/W |
RθJB | Junction-to-board thermal resistance | 33.8 | °C/W |
ψJT | Junction-to-top characterization parameter | 2.9 | °C/W |
ψJB | Junction-to-board characterization parameter | 33.5 | °C/W |
RθJCbot | Junction-to-case (bottom) thermal resistance | 16.3 | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
IVBUS | VBUS Operating Current Consumption | No load on VBUS_OUT pin, VBUS = 5 V, EN = 0 V |
147.6 | 160 | µA | |
IVBUS_OFF | VBUS Operating Current Consumption | No load on VBUS_OUT pin, VBUS = 5 V, EN = 5 V |
111.8 | 120 | µA |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
TSHDN | Thermal Shutdown | 144 | °C | |||
TSHDN-HYS | Thermal-Shutdown Hysteresis | 23 | °C |
The TPD4S014 provides a single-chip protection solution for USB charger interfaces. The VBUS line is tolerant up to 28 V DC. A Low RON nFET switch is used to disconnect the downstream circuits in case of a fault condition. At power-up, when the voltage on VBUS is rising, the switch will close 17 ms after the input crosses the under voltage threshold, thereby making power available to the downstream circuits. The TPD4S014 also has an ACK output, which de-asserts to alert the system a fault has occurred. The TPD4S014 offers 4 channel ESD clamps for D+, D-, ID, and VBUS pins that provide IEC61000-4-2 level 4 ESD protection. This eliminates the need for external TVS clamp circuits in the application.
When the input voltage rises above VOVP, or drops below the VUVLO, the internal VBUS switch is turned off, removing power to the application. The ACK signal is de-asserted when a fault condition is detected. If the fault was an over voltage event, the VBUS nFET switch turns on 8 ms (tREC) after the input voltage returns below VOVP – VHYS_OVP and remains above VUVLO. If the fault was an under voltage event, the switch turns on 17 ms after the voltage returns above VUVLO+ (similar to start up). When the switch turns on, the ACK is asserted once again.
The nFET switch has a total on resistance (RON) of 151 mΩ. This equates to a voltage drop of 302 mV when charging at the maximum 2.0 A current level. Such low RON helps provide maximum potential to the system as provided by an external charger.
The D+, D–, ID, and VBUS pins can withstand ESD events up to ±15-kV contact and air-gap. An ESD clamp diverts the current to ground.
The over voltage and under voltage lockout feature ensures that if there is a fault condition at the VBUS line, the TPD4S014 is able to isolate the VBUS line and protect the internal circuitry from damage. Due to the body diode of the nFET switch, if there is a short to ground on VBUS the system is expected to limit the current to VBUSOUT.
The D+/D– ESD protection pins have low capacitance so there is no significant impact to the signal integrity of the USB 2.0 Hi-Speed data rate.
Upon startup, TPD4S014 has a built in startup delay. An internal oscillator controls a charge pump to control the turn-on delay (tON) of the internal nFET switch. The internal oscillator controls the timers that enable the turn-on of the charge pump and sets the state of the open-drain ACK output. If VBUS < VUVLO or if VBUS > VOVLO, the internal oscillator remains off, thus disabling the charge pump. At any time, if VBUS drops below VUVLO or rises above VOVLO, ACK is released and the nFET switch is disabled.
A 17 ms deglitch time has been introduced into the turn on sequence to ensure that the input supply has stabilized before turning the nFET switch ON. Noise on the VBUS line could turn ON the nFET switch when the fault condition is still active. To avoid this, OVP glitch immunity allows noise on the VBUS line to be rejected. Such a glitch protection circuitry is also introduced in the turn off sequence in order to prevent the switch from turning off for voltage transients. The glitch protection circuitry integrates the glitch over time, allowing the OVP circuitry to trigger faster for larger voltage excursions above the OVP threshold and slower for shorter excursions.
External control of the nFET switch is provided by an active low EN pin. An ACK pin provides output logic to acknowledge VBUS is between UVLO and OVP by asserting low.
When the device is ON, current flowing through the device will cause the device to heat up. Overheating can lead to permanent damage to the device. To prevent this, an over temperature protection has been designed into the device. Whenever the junction temperature exceeds 145ºC, the switch will turn off, thereby limiting the temperature. The ACK signal will be asserted for an over temperature event. Once the device cools down to below 120ºC the ACK signal will be de-asserted, and the switch will turn on if the EN is active and the VBUS voltage is within the UVLO and OVP thresholds. While the over temperature protection in the device will not kick-in unless the die temperature reaches 145ºC, it is generally recommended that care is taken to keep the junction temperature below 125 ºC. Operation of the device above 125 ºC for extended periods of time can affect the long-term reliability of the part.
The junction temperature of the device can be calculated using below formula:
where
where
Example
At 2-A continuous current power dissipation is given by:
If the ambient temperature is about 60°C the junction temperature will be:
This implies that, at an ambient temperature of 60ºC, TPD4S014 can pass a continuous 2 A without sustaining damage. Conversely, the above calculation can also be used to calculate the total continuous current the TPD4S014 can handle at any given temperature.
Table 1 is the function table for TPD4S014.
OTP | UVLO | OVLO | EN | SW | ACK |
---|---|---|---|---|---|
X | H | X | X | OFF | H |
X | X | H | X | OFF | H |
L | L | L | H | OFF | L |
L | L | L | L | ON | L |
H | X | X | X | OFF | H |
OTP = | Over temperature protection circuit active |
UVLO = | Under voltage lock-out circuit active |
OVLO = | Over voltage lock-out circuit active |
SW = | Load switch |
CP = | Charge pump |
X = | Don’t Care |
H = | True |
L = | False |
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The TPD4S014 is a single-chip solution for USB charger port protection. This device offers low capacitance TVS type ESD clamps for the D+, D–, and standard capacitance for the ID pin. On the VBUS pin, this device can handle over voltage protection up to 28 V. The over voltage lockout feature ensures that if there is a fault condition at the VBUS line TPD4S014 is able to isolate the VBUS line and protect the internal circuitry from damage. In order to let the voltage stabilize before closing the switch there is a 17 ms turn on delay after VBUS crosses the UVLO threshold. This function acts as a de-glitch which prevents unnecessary switching if there is any ringing on the line during connection. Due to the body diode of the nFET switch, if there is a short to ground on VBUS the system is expected to limit the current to VBUSOUT.
Table 2 shows the design parameters.
DESIGN PARAMETERS | EXAMPLE VALUE |
---|---|
Signal range on VBUS | 3.3 V – 5.9 V |
Signal range on VBUSOUT | 3.9 V – 5.9 V |
Signal range on D+/D– and ID | 0 V – 5 V |
Drive EN low (enabled) | 0 V – 0.5 V |
Drive EN high (disabled) | 1 V – 6 V |
To begin the design process, some parameters must be decided upon. The designer needs to know the following:
Table 3 shows the design parameters.
DESIGN PARAMETERS | EXAMPLE VALUE |
---|---|
Signal range on VBUS | 3.3 V – 5.9 V |
Signal range on VBUSOUT | 3.9 V – 5.9 V |
Signal range on D+/D– and ID | 0 V – 5 V |
Drive EN low (enabled) | 0 V – 0.5 V |
Drive EN high (disabled) | 1 V – 6 V |
To begin the design process, some parameters must be decided upon. The designer needs to know the following:
Refer to Application Curves in the previous section.
TPD4S014 Is designed to receive power from a USB 3.0 (or lower) VBUS source. It can operate normally (nFET ON) between 3.0 V and 5.9 V. Thus, the power supply (with a ripple of VRIPPLE) requirement for TPD4S014 to be able to switch the nFET ON is between 3.0 V + VRIPPLE and 5.9 V – VRIPPLE.