TPS92630-Q1 3チャネル・リニアLEDドライバ、アナログおよびPWM調光機能付き

1 特長

• 車載アプリケーション用に認定済み
• 下記内容でAEC-Q100認定済み:
  • デバイス温度グレード1: 動作時周囲温度範囲　　　　–40°C～125°C
  • デバイスHBM ESD分類レベルH2
  • デバイスCDM ESD分類レベルC3B
• アナログおよびPWM調光機能を持つ3チャネルのLEDドライバ
• 広い入力電圧範囲: 5V～40V
• 基準抵抗を使用して定出力電流を調整可能
  • 最大電流: チャネルごとに150mA
  • 並列動作モードでの最大電流: 450mA
  • 精度: チャネルごとに±1.5% (I_(IOUTx) > 30mAのとき)
  • 精度: デバイスごとに±2.5% (I_(IOUTx) > 30mAのとき)
• 複数のICまたは単一ICの複数チャネルを使用した並列出力によってさらに高い電流を供給可能
• 低いドロップアウト電圧
  • 最大ドロップアウト: 60mAでチャネルごとに400mV
  • 最大ドロップアウト: 150mAでチャネルごとに0.9V
• チャネルごとに独立したPWM調光
• グリッチ除去タイマを備えたオープン/短絡LED検出
• チャネルごとのLEDストリング電圧帰還による単一LEDの短絡検出
• 単一LED短絡障害専用の独立したフォルト・ピン
• オープン、短絡、サーマル・シャットダウンの障害通知用のフォルト・ピンに15までのデバイスを並列にバス接続可能
• 入力電圧のdV/dtが低い場合(0.5V/min)にも問題なく対応
• 動作時の接合部温度範囲: -40℃～150℃
• パッケージ: 放熱特性の優れた16ピンPWPパッケージ(HTSSOP)

2 アプリケーション

次のような車載用LED照明アプリケーション

• 昼間走行灯
• 車幅灯
• フォグランプ
• 尾灯
• ストップ/テールランプ
• 室内照明

3 概要

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。

1. 提供されているすべてのパッケージについては、データシートの末尾にある注文情報を参照してください。

Device Images

代表的なアプリケーションの回路図

4 改訂履歴

Changes from D Revision (January 2018) to E Revision

• 「代表的なアプリケーションの回路図」で出力にコンデンサを追加Go
• Changed V_IH and V_IL logic-level values for the PWMx pinsGo
• Changed parameter description for I_(pullup) from strong to weak pullup currentGo
• Added capacitors to the outputs on Figure 26Go
• Added the Input and Output Capacitors sectionGo
• Added capacitors to the outputs on Figure 28Go
• Added the Input and Output Capacitors sectionGo
• Added capacitors to the outputs on Figure 29Go
• Added the Input and Output Capacitors sectionGo
• Added capacitors to the outputs on Figure 30Go
• Added the Input and Output CapacitorsGo
• Added capacitors to the outputs on Figure 31Go
• Added the Input and Output Capacitors sectionGo

Changes from C Revision (November 2017) to D Revision

• Changed pinout diagramGo
• Changed text for the Thermal pad row in the DESCRIPTON columnGo

Changes from B Revision (January 2015) to C Revision

• TPS92630-Q1の型番をページ・ヘッダから削除Go
• データシート・タイトルのTPS9263x-Q1をTPS92630-Q1に変更Go
• 「2つのオプション」項目を特長のリストから削除Go
• TPS92631-Q1デバイスを製品情報の表から削除Go
• Changed pinout diagramGo
• Deleted the COMMENT column and moved the comment text to the DESCRIPTION columnGo
• Added a row for thermal pad informationGo
• Deleted specifications pertaining to the TPS92631-Q1 deviceGo
• Changed figure reference in the FAULT Diagnostics section to Figure 19Go
• ドキュメントの更新通知を受け取る方法およびコミュニティ・リソースのセクションを追加Go

Changes from A Revision (December 2014) to B Revision

• Changed pin numbers for IOUT1 and IOUT3 in Pin Functions table Go

Changes from * Revision (February 2014) to A Revision

• Changed pin numbers and comments in Pin Functions table for pins 14 and 16 Go
• Changed Changed the Handling Ratings table to ESD Ratings and moved storage temperature to the Absolute Maximum Ratings table Go
• Changed the MAX value for the EN internal pulldown parameter from 2.5 to 5 µA in the Electrical Characteristics table Go
• Added MAX value for T_(shutdown)Go
• Changed Figure 24Go
• Changed Figure 25Go
• Changed voltage on pullup resistor from 3 V to 3.3 V Go
• Changed board layout diagram Go

5 概要(続き)

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。

6 Pin Configuration and Functions

7 Specifications

7.1 Absolute Maximum Ratings⁽¹⁾

7.2 ESD Ratings

7.3 Recommended Operating Conditions

7.4 Thermal Information

7.5 Electrical Characteristics

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 (1)	–3%		3%
		30 mA ≤ I(IOUTx) < 150 mA, Vin = 5 V–40 V (1)	–1.5%		1.5%
ΔIO(device)	Device accuracy	10 mA < I(IOUTx) < 30 mA, V(VIN) = 5 V to 20 V(2) (3)	–4%		4%
		30 mA ≤ IOUT < 150 mA, V(VIN) = 5 V to 20 V(2) (3)	–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

7.6 Timing Requirements

7.7 Typical Characteristics

TA = 25ºC

V(VIN) = 14 V

Three LEDs

Figure 1. Current Accuracy vs Current Setting

V(VIN) = 20 V

I(setting) = 150 mA

Figure 3. Device Current Accuracy vs Input Voltage

3 white LEDs

LEDs in series

I(setting) = 150 mA

Figure 5. Output Current vs Input Voltage

I(setting)= 150 mA

V(VIN) = 14 V

Figure 7. Output Current vs Ambient Temperature

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 200 Hz	Duty cycle = 10%

Figure 9. PWM Dimming

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 200 Hz	Duty cycle = 90%

Figure 11. PWM Dimming

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 2000 Hz	Duty cycle = 50%

Figure 13. PWM Dimming

I(setting) = 60 mA

Figure 15. Fast Power-Up Waveform

V(VIN) = 20 V

I(setting) = 30 mA

Figure 2. Device Current Accuracy vs Input Voltage

A

Figure 4. Output Current vs External Resistance

I(setting) = 30 mA

V(VIN) = 14 V

Figure 6. Output Current vs Ambient Temperature

A

Figure 8. Reference Voltage vs Junction Temperature With Thermal Foldback

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 200 Hz	Duty cycle = 50%

Figure 10. PWM Dimming

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 2000 Hz	Duty cycle = 10%

Figure 12. PWM Dimming

Ch. 1 = PWM input	Ch. 2 = IOUT1	Ch. 3 = IOUT2
Ch. 4 = IOUT3	f(PWM) = 2000 Hz	Duty cycle = 90%

Figure 14. PWM Dimming

V(VIN) = V(EN)	V(VIN) = 0 V to 12 V	I(setting) = 60 mA
3 white LEDs	dV/dt = 0.5 V/min

Figure 16. Slow Power-Up Waveform

8 Parameter Measurement Information

Figure 17. Load Model for Slew-Rate and Delay-Time Tests

9 Detailed Description

9.1 Overview

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.

9.2 Functional Block Diagram

9.3 Feature Description

9.3.1 Constant LED-Current Setting

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:

Equation 1.

9.3.2 PWM Control

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.

9.3.3 FAULT Diagnostics

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.

Figure 18. Detailed Timing Diagram

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.

Figure 19. 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.

Figure 20. Detailed Timing Diagram

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.

9.3.4 Short-Circuit Detection

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.

Figure 21. 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.

• The device reports the failure to the MCU. The faulted channel continues sourcing current until the MCU takes actions to turn off channels through the EN or PWMx pin.
• No MCU: with FAULT_S floating, no action results. With FAULT_S tied to FAULT, all output channels shut down together.

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.

• V_F(max) – maximum forward voltage of LED used
• V_F(min) – minimum forward voltage of LED used
• N – Number of LEDs used in a string
• R – resistor divider ratio
• V_(VSNSx) – internal reference voltage of comparators

When selecting R, observe the following relationship to avoid false triggering.

Figure 22. Single-LED Short-Trigger Calculation

9.3.5 Open-Load Detection

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.

9.3.6 Thermal Foldback

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.

Figure 23. Thermal Foldback

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:

Figure 24. TEMP Pin Voltage vs Temperature

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. Pullup and Pulldown Resistors vs 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.

9.4 Device Functional Modes