次のような車載用LED照明アプリケーション
TPS92630-Q1デバイスは、アナログおよびPWM調光制御を備えた3チャネル・リニアLEDドライバです。完全な診断機能および内蔵保護機能により、中電力範囲までの可変輝度LED照明アプリケーションに最適な選択肢となります。
型番 | パッケージ(ピン) | 本体サイズ(公称) |
---|---|---|
TPS92630-Q1 | HTSSOP (16) | 4.40mm×5.00mm |
Changes from D Revision (January 2018) to E Revision
Changes from C Revision (November 2017) to D Revision
Changes from B Revision (January 2015) to C Revision
Changes from A Revision (December 2014) to B Revision
Changes from * Revision (February 2014) to A Revision
このデバイスの設計は、その電力容量の範囲内で単一または複数のストリングとして構成されたLEDを駆動するのに適しています。1つのデバイスで最大3つのストリング(各ストリングに1~3個のLED)を駆動でき、1チャネルあたりの合計電流は最大150mAです。出力を並列に接続することで、さらに高い電流駆動能力(最大450mA)を実現できます。
複数ストリングのアプリケーションでは、LEDストリングをカソード・コモンで接続できるという利点があります。そのため、(ローサイド電流センスのシステムのように) LEDストリングごとに1本のリターン線を設ける代わりに、アプリケーション全体で1本のリターン線だけで済みます。
単一LEDの短絡コンパレータにより、短絡障害が発生した単一のLEDを検出できます。障害出力では、複数デバイス間のバス接続トポロジをサポートできます。
内蔵の温度監視機能により、デバイスの接合部温度がスレッショルドを超えた場合に、LEDの駆動電流を低減します。温度スレッショルドは、外付け抵抗を使用してプログラミングできます。TEMPピンをグランドに接続すると、温度電流監視機能をディスエーブルにできます。出荷時設定オプションとして、接合部温度のアナログ電圧出力も用意されています。
MIN | MAX | UNIT | ||
---|---|---|---|---|
VIN, IOUTx, PWMx, EN, VSNSx | Unregulated input(2)(3)(4) | –0.3 | 45 | V |
FAULT, FAULT_S | See (2) | –0.3 | 22 | V |
Others | See (2) | –0.3 | 7 | V |
Virtual junction temperature, TJ | –40 | 150 | °C | |
Operating ambient temperature, TA | –40 | 125 | °C | |
Storage temperature, Tstg | –65 | 150 | °C |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | ±2000 | V | |
Charged-device model (CDM), per AEC Q100-011 | Corner pins (1, 8, 9, and 16) | ±750 | ||
Other pins | ±500 |
MIN | MAX | UNIT | ||
---|---|---|---|---|
VIN | 5 | 40 | V | |
PWMx, EN, VSNSx | 0 | 40 | V | |
FAULT, FAULT_S | 0 | 20 | V | |
Others | 0 | 5 | V | |
TJ | Operating junction temperature range | –40 | 150 | °C |
THERMAL METRIC(2) | TPS92630-Q1 | UNIT | |
---|---|---|---|
PWP (HTSSOP) | |||
16 PINS | |||
RθJA | Junction-to-ambient thermal resistance(1) | 41.5 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 29.6 | °C/W |
RθJB | Junction-to-board thermal resistance | 24 | °C/W |
ψJT | Junction-to-top characterization parameter | 1 | °C/W |
ψJB | Junction-to-board characterization parameter | 23.8 | °C/W |
RθJC(bot) | Junction-to-case (bottom) thermal resistance | 3.4 | °C/W |
PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
SUPPLY VOLTAGE AND CURRENT (VIN) | ||||||
VI | Input voltage | 5 | 40 | V | ||
I(quiescent) | Quiescent current | All PWMx = high, I(IOUTx) = 100 mA,
Not including Iref |
0.5 | 0.6 | 0.85 | mA |
IO(sd) | Shutdown current | V(EN) = 0 V | 10 | µA | ||
I(fault) | Shutdown current in fault mode (device to GND) | PWM = EN = high, FAULT = low, V(VIN) = 5 V–40 V, I = 100 mA | 0.5 | 0.6 | 0.85 | mA |
Shutdown current in fault mode (from V(VIN)) | PWM = EN = high, FAULT = low, V(VIN) = 5 V–40 V, I = 100 mA | 2 | ||||
PWMx AND EN | ||||||
VIL(EN) | Logic input, low level | IOUTx disabled | 0 | 0.7 | V | |
VIH(EN) | Logic input, high level | IOUTx enabled | 2 | V | ||
I(EN-pd) | EN internal pulldown | V(EN) = 0 V to 40 V | 0.35 | 5 | µA | |
VIL(PWMx) | Logic input, low level | IOUTx disabled | 1.135 | 1.195 | 1.255 | V |
VIH(PWMx) | Logic input, high level | IOUTx enabled | 1.161 | 1.222 | 1.283 | V |
Vhys(PWM) | Hysteresis | 44 | mV | |||
I(PWM-pd) | PWMx internal pulldown current | V(PWMx) = 40 V | 100 | 180 | 250 | nA |
CURRENT REGULATION (IOUTx) | ||||||
I(IOUTx) | Regulated output current range | Each channel | 10 | 150 | mA | |
Three channels in parallel mode | 30 | 450 | ||||
ΔIO(channel) | Channel accuracy | 10 mA < I(IOUTx) < 30 mA, V(VIN) = 5 V–40 V
![]() |
–3% | 3% | ||
30 mA ≤ I(IOUTx) < 150 mA, Vin = 5 V–40 V
![]() |
–1.5% | 1.5% | ||||
ΔIO(device) | Device accuracy | 10 mA < I(IOUTx) < 30 mA, V(VIN) = 5 V to 20 V(2)
![]() |
–4% | 4% | ||
30 mA ≤ IOUT < 150 mA, V(VIN) = 5 V to 20 V(2)
![]() |
–2.5% | 2.5% | ||||
Vref | Reference voltage | 1.198 | 1.222 | 1.246 | V | |
K(I) | Ratio of I(IOUTx) to reference current | 100 | ||||
V(DROP) | Dropout voltage | At 150 mA load per channel | 0.6 | 0.9 | V | |
At 60 mA load per channel | 0.24 | 0.4 | ||||
SR | Current rise and fall slew rates | Current rising from 10% to 90% or falling from 90% to 10% at I(IOUTx) = 60 mA.(4) | 4 | 8 | 15 | mA/µs |
Current rising from 10% to 90% or falling from 90% to 10% at I(IOUTx) = 150 mA.(4) | 7 | 14 | 25 | mA/µs | ||
FAULT (FAULT) | ||||||
VIL | Logic input low threshold | 0.7 | V | |||
VIH | Logic input high threshold | 2 | V | |||
VOL | Logic output low level | Tested with 500-µA external pullup | 0.7 | V | ||
VOH | Logic output high level | Tested with 1-µA external pulldown | 2 | V | ||
I(pulldown) | Strong pulldown current | 500 | 750 | 1000 | µA | |
I(pullup) | Weak pullup current | 4 | 8 | 16 | µA | |
COMPARATOR (VSNSx) | ||||||
V(VSNSx) | Internal comparator reference (for short circuit detection) | V(VIN) > V(th) | 1.198 | 1.222 | 1.246 | V |
Ilkg | Leakage current | V(VSNSx) = 3 V | 500 | nA | ||
V(th) | Voltage at which the chip enables the single-short alarm function | Single-short detection enabled | 8 | 9 | V | |
V(th) hysteresis | 145 | mV | ||||
PROTECTION | ||||||
V(OLV) | Open-load detection voltage | V(OLV) = V(VIN) – V(IOUTx) | 50 | 100 | 150 | mV |
V(OL-hys) | Open-load detection hysteresis | 100 | 200 | 300 | mV | |
V(SV) | Short-detection voltage | 0.846 | 0.89 | 0.935 | V | |
Short-detection hysteresis | 318 | 335 | 352 | mV | ||
Short-detection deglitch | 1 | 2 | 3 | ms | ||
During PWM, count the number of continuous cycles when V(IOUTx) < V(SV) | 7 | 8 | Cycles | |||
R(REF_open) | REF pin resistor open detection | FAULT goes low | 15 | 23 | 57 | kΩ |
R(REF_short) | REF pin resistor short detection | FAULT goes low | 350 | 470 | 800 | Ω |
THERMAL MONITOR | ||||||
T(shutdown) | Thermal shutdown | 155 | 170 | 170 | °C | |
T(hys) | Thermal shutdown hysteresis | 15 | °C | |||
T(th) | Thermal foldback activation temperature | 90% of I(IOUTx) normal (TEMP pin floating) | 95 | 110 | 125 | °C |
I(TFCmin) | Minimum foldback current | 40% | 50% | 60% | ||
V(T-disable) | Thermal-foldback-function disable voltage | 0 | 0.2 | V |
MIN | NOM | MAX | UNIT | |||
---|---|---|---|---|---|---|
t(startup) | Start-up time | V(VIN) > 5 V, I(IOUTx) = 50%, I(setting) = 60 mA(1) | 200 | µs | ||
td(on) | Delay time between PWM rising edge to 10% of I(IOUTx) | Two LEDs in series, 10-kΩ resistor in parallel | 14 | 30 | µs | |
td(off) | Delay time between PWM falling edge to 90% of I(IOUTx) | Two LEDs in series, 10-kΩ resistor in parallel | 25 | 45 | µs | |
Single-short detection deglitch | 1 | 2 | 3 | ms | ||
During PWM, count the number of continuous cycles when V(VSNSx) < 1.24 V | 7 | 8 | Cycles | |||
Open-load detection deglitch | 1 | 2 | 3 | ms | ||
During PWM, count the number of continuous cycles when V(VIN) – V(IOUTx) < V(OLV) | 7 | 8 | Cycles | |||
Short-detection deglitch | 1 | 2 | 3 | ms | ||
During PWM, count the number of continuous cycles when V(IOUTx) < V(SV) | 7 | 8 | Cycles |
TA = 25ºC | V(VIN) = 14 V | Three LEDs |
V(VIN) = 20 V | I(setting) = 150 mA |
3 white LEDs | LEDs in series | I(setting) = 150 mA |
I(setting)= 150 mA | V(VIN) = 14 V |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 200 Hz | Duty cycle = 10% |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 200 Hz | Duty cycle = 90% |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 2000 Hz | Duty cycle = 50% |
I(setting) = 60 mA | ||
V(VIN) = 20 V | I(setting) = 30 mA |
A |
I(setting) = 30 mA | V(VIN) = 14 V |
A |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 200 Hz | Duty cycle = 50% |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 2000 Hz | Duty cycle = 10% |
Ch. 1 = PWM input | Ch. 2 = IOUT1 | Ch. 3 = IOUT2 |
Ch. 4 = IOUT3 | f(PWM) = 2000 Hz | Duty cycle = 90% |
V(VIN) = V(EN) | V(VIN) = 0 V to 12 V | I(setting) = 60 mA |
3 white LEDs | dV/dt = 0.5 V/min |
The TPS92630-Q1 device is a three-channel constant-current regulator with individual PWM dimming, designed for high brightness red or white LEDs in automotive lighting applications. Each channel has up to 150-mA current capability, giving a combined 450-mA current capability when paralleled. The device provides excellent current matching between channels and devices. A high-side current source allows LED common-cathode connections. The advanced control loop allows high accuracy between channels, even when different numbers of LEDs are connected on the output. Use of a separate PWM channel dims or disables each channel.
The TPS92630-Q1 device monitors fault conditions on the output and reports its status on the FAULT and FAULT_S pins. It features single-shorted-LED detection, output short-to-ground detection, open-load detection, and thermal shutdown. Two separate fault pins allow maximum flexibility of fault-mode reporting to the MCU in case of an error. In case there is no MCU, one can connect multiple TPS92630-Q1 devices in a bus mode.
Integrated thermal foldback protects the devices from thermal shutdown by reducing the output current linearly when reaching a preset threshold. Use an external resistor to program the temperature foldback threshold. Tying the TEMP pin to ground disables this function.
Control of the three LED output channels is through separate linear current regulators. A common external resistor sets the current in each channel. The device also features two current levels with external circuitry, intended for stop- and tail-light applications.
See Equation 1 on how to set the current:
The device features a separate PWM dimming control pin for each output channel. PWM inputs also function as shutdown pin when an output is unused. Tying PWM to ground disables the corresponding output. The PWM signal has a precise threshold, which one can use to define the start-up voltage of LED as an undervoltage-lockout (UVLO) function with the divider resistor from the VIN pin.
The TPS92630-Q1 device has two fault pins, FAULT and FAULT_S. FAULT_S is a dedicated fault pin for single-LED short failure and FAULT is for general faults, that is, short, open, and thermal shutdown. The dual pins allow maximum flexibility based on all requirements and application conditions.
The device fault pins can be connected to an MCU for fault reporting. Both fault pins are open-drain transistors with a weak internal pullup. See Figure 19.
In case there is no MCU, one can connect up to 15 TPS92630-Q1 FAULT and FAULT_S pins together. When one or more devices have errors, the respective FAULT̅ pins go low, pulling the connected FAULT bus down and shutting down all device outputs. Figure 19 shows the fault-line bus connection.
The device releases the FAULT bus when external circuitry pulls the FAULT pin high, on toggling of the EN pin, or on a power cycle of the device. In case there is no MCU, only a power cycle clears the fault. See Figure 20.
The following faults result in the FAULT or FAULT_S pin going low: thermal shutdown, open load, output short circuit, single LED short, and REF open or shorted. For thermal shutdown or LED open, release of the FAULT pin occurs when the thermal-shutdown or LED-open condition no longer exists. For other faults, the FAULT and FAULT_S pins stay low even if the condition does not exist. Clearing the faults requires a power cycle of the device.
The device includes three internal comparators for LED forward-voltage measurement. With external resistor dividers, the device compares total LED forward voltage with the internal reference voltage. This feature enables the detection of one or more shorted LEDs. Any LED cathode or IOUTx pin shorted to ground results in a short-circuit condition. The external resistor dividers control the detection-threshold-voltage setting.
Figure 21 illustrates different short-circuit conditions.
A short in one or more LEDs in a string (A and B as illustrated) registers as only a single-LED short when V(VIN) > 9 V.
When an entire string of LEDs is shorted (C as illustrated), the device pulls FAULT low to shut down all channels. With the FAULT pin tied high, only the faulted channel turns off.
When selecting R, observe the following relationship to avoid false triggering.
Detection of an open-load condition occurs when the voltage across the channel, V(VIN) – V(IOUTx), is less than the open-load detection voltage, V(OLV). When this condition is present for more than the open-load-detection deglitch (2 ms when PWM is 100% on or one PWM on-time is more than 2 ms, or seven continuous PMW duty cycles when in PWM dimming mode), the FAULT pin goes low, keeping the open channel on and turning the other channel off. With the FAULT pin tied high, all channels remain turned on. The channel recovers on removal of the open condition. Note that the device can detect an open load if the sum of the forward voltages of the LEDs in a string is close to or greater than the supply voltage on VIN.
FAILURE MODE | JUDGMENT CONDITION | DIAGNOSTIC OUTPUT PINS | ACTION | FAULT AND FAULT_S(3) | DEVICE REACTION | FAILURE
REMOVED |
SELF-
CLEARING |
||
---|---|---|---|---|---|---|---|---|---|
DETECTION
VIN VOLTAGE |
CHANNEL STATUS | DETECTION MECHANISM | |||||||
Short circuit:
1 or several LED strings |
V(VIN) > 5 V | ON | V(IOUTx) < 0.9 V | FAULT | Pulled low | Externally
pulled high |
Failing strings turned off, other channels on | Toggle EN,
power cycle |
No |
Floating | All strings turned OFF | Toggle EN,
power cycle |
|||||||
Single-LED short circuit:
1 or several LED strings |
V(VIN) > 9 V | ON | V(VSNSx) < 1.222 V | FAULT_S | Pulled low | Externally
pulled high |
All strings stay ON | Toggle EN,
power cycle |
No |
Floating | All strings stay ON | Toggle EN,
power cycle |
|||||||
Open load:
1 or several LED strings |
V(VIN) > 5 V | ON | V(VIN) – V(IOUTx)
< 100 mV |
FAULT | Pulled low | Externally
pulled high |
All strings stay ON | Yes | |
Floating | Failing string stays ON, other channels turned OFF | ||||||||
Short to battery:
1 or several LED strings |
V(VIN) > 5 V | ON or OFF | V(VIN) – V(IOUTx)
< 100 mV |
FAULT | Pulled low | Externally
pulled high |
All strings stay ON | Yes | |
Floating | Failing string stays ON, other channels turned OFF | ||||||||
Thermal shutdown | V(VIN) > 5 V | ON or OFF | Temperature > 170°C | FAULT | Pulled low | Externally
pulled high |
All strings turned OFF | Temperature < 155°C | Yes |
Leave open | |||||||||
Thermal foldback | V(VIN) > 5 V | ON or OFF | Temperature > 110°C | N/A | None | N/A | All strings with
reduced current |
Temperature < 100°C | Yes |
Reference resistor
open or shorted |
V(VIN) > 5 V | ON or OFF | R(REF) > 57 kΩ
or R(REF) < 350 Ω |
FAULT | Pulled low | N/A | All strings turned OFF | Toggle EN,
power cycle |
No |
The TPS92630-Q1 device integrates thermal shutdown protection to prevent the device from overheating. In addition, to prevent LEDs from flickering because of rapid thermal changes, the device includes a programmable thermal current-foldback feature to reduce power dissipation at high junction temperatures.
The TPS92630-Q1 device reduces the LED current as the silicon junction temperature of the TPS92630-Q1 device increases (see Figure 23). By mounting the TPS92630-Q1 device on the same thermal substrate as the LEDs, use of this feature can also limit the dissipation of the LEDs. As the junction temperature of the TPS92630-Q1 device increases, the device reduces the regulated current, reducing the dissipated power in the TPS92630-Q1 device and in the LEDs. The current reduction is from the 100% level at typically 2% of I(setting) per ºC until the point at which the current drops to 50% of the full value.
Above this temperature, the current continues to decrease at a lower rate until the temperature reaches the overtemperature shutdown threshold temperature, T(shutdown). Changing the voltage on the TEMP pin adjusts the temperature at which the current reduction begins. With TEMP floating, the definition of thermal monitor activation temperature, T(th), is the temperature at which the current reduction begins. The specification of T(th) in the characteristics table is at the 90% current level. T(th) increases as the voltage at the TEMP pin, V(TEMP), declines and is defined as approximately:
A resistor connected between TEMP and GND reduces V(TEMP) and increases T(th). A resistor connected between TEMP and a reference supply greater than 1 V increases V(TEMP) and reduces T(th).
Figure 25 shows how the nominal value of the thermal-monitor activation temperature varies with the voltage at TEMP and with either a pulldown resistor to GND or with a pullup resistor to 3.3 V or 5 V.
In extreme cases, if the junction temperature exceeds the overtemperature limit, T(shutdown), the device disables all channels. Temperature monitoring continues, and channel reactivation occurs when the temperature drops below the threshold provided by the specified hysteresis.
Note the possibility of the TPS92630-Q1 device transitioning rapidly between thermal shutdown and normal operation. This can happen if the thermal mass attached to the exposed thermal pad is small and T(th) is increased to close to the shutdown temperature. The period of oscillation depends on T(th), the dissipated power, the thermal mass of any heatsink present, and the ambient temperature.