TI TPS929121-Q1：12通道汽车级高侧LED驱动器

需积分: 14 2 浏览量更新于2024-06-29 5 收藏 8.42MB PDF 举报

"TI-TPS929121-Q1.pdf 是德州仪器（TI）推出的一款适用于汽车应用的12通道高边LED驱动器，具备 FlexWire 控制接口和多种保护功能。" TI 的 TPS929121-Q1 是一款经过AEC-Q100认证的汽车级集成电路，设计用于在-40°C至+125°C的工作温度范围内稳定工作。这款器件的主要特点在于其12个通道的精确高侧电流输出，能够处理4.5V至40V的电源电压。每个通道的电流可以通过外部电阻设定，最大可达到75mA，且具有高精度，电流误差小于±5%在5mA到75mA的范围内，甚至在1mA时也能保持小于±10%的精度。驱动器的压降低，仅为500mV在50mA负载下。 TPS929121-Q1 提供了2位全局和6位独立的电流设置，以及12位独立的PWM调光功能，支持高达20kHz的可编程PWM频率。调光方式包括线性和指数两种，以满足不同应用场景的需求。FlexWire控制接口允许高达1MHz的时钟频率，单个FlexWire总线上可以连接最多16个设备，并且在一个帧内能完成最多8字节的数据传输。此外，该驱动器还集成了一个5V LDO输出，可用于供电CAN收发器。在诊断和保护功能方面，TPS929121-Q1具备可编程的故障安全状态、LED开路检测、短路检测，甚至可以进行单个LED短路诊断。它还设有可编程的低电压检测，开放漏极ERR引脚用于故障指示，以及针对FlexWire接口的看门狗和CRC校验功能，确保通信的可靠性。此外，集成的8位ADC用于测量引脚电压，确保系统运行的稳定性。最后，还包括过温保护机制，以防止设备在高温环境下损坏。 TPS929121-Q1是一款高性能、高可靠性的汽车LED驱动器，适用于需要精确控制和多种保护功能的汽车照明系统。其FlexWire接口和强大的诊断功能使其在汽车电子领域中具有广泛的应用潜力。

Upon powering up, the TPS929121-Q1 automatically loads all settings stored in EEPROM to correlated registers

and sets the other registers to default value which don't have correlated EEPROM. All channels are powered up

in off-state by default to avoid unwanted blinking.

Writing 1 to CLR_REG manually loads EEPROM setting to the correlated registers and set the other registers to

default value. After CLR_REG is set, the FLAG_POR is set 1 to indicate registers clear to default values. Writing

1 to CLR_POR resets the FLAG_POR register to 0. TI recommends settting CLR_REG to 1 to clear the internal

registers every time after POR. The CLR_REG automatically resets to 0.

8.3.1.4 Programmable Low Supply Warning

The TPS929121-Q1 uses its internal ADC to monitor supply voltage V

(SUPPLY)

. If the supply is below allowable

working threshold, the output voltage may not be sufficient to keep the LED operating with desired brightness

output as expected. The ADC output is automatically compared with threshold set by register

CONF_ADCLOWSUPTH as described in Register Maps. When the supply voltage is below threshold, the device

sets warning flag register FLAG_ADCLOWSUP to 1 in the status register. CLR_FAULT is able to clear the

FLAG_ADCLOWSUP as well as other fault registers. In addition, the LED open-circuit and single LED short-

circuit detection is disabled if the supply voltage is below threshold to avoid LED open circuit and to prevent the

single LED short-circuit fault from being mis-triggered. The 4-bit register CONF_ADCLOWSUPTH has total 15

options covering from 5 V to 20 V.

8.3.2 Constant Current Output

8.3.2.1 Reference Current With External Resistor (REF)

The TPS929121-Q1 must have an external resistor R

(REF)

to set the internal current reference I

(REF)

as shown in

Figure 8-1.

Optional

REF

1.235V

(REF)

×512

×256

×128

×64

2-bit range selection

6-bit DAC

CH0

6-bit DAC

CH1

6-bit DAC

CH11

OUT0

OUT1

OUT11

REF

(FULL_RANGE)

CONF_REFRANGE[1:0]

CONF_IOUT0[5:0]

(REF)

1.235V

REF

CONF_IOUT1[5:0]

CONF_IOUT11[5:0]

Figure 8-1. Output Current Setting

The internal current reference I

(FULL_RANGE)

is generated based on the I

(REF)

multiplied by factor K

(REF)

to provide

the full range current reference for each OUTx channel. The K

(REF)

is programmable by 2-bit register

CONF_REFRANGE with 4 different options. The I

(FULL_RANGE)

can be calculated with Equation 1.

(REF)

(FULL _ RANGE) (REF)

(REF)

I K

(1)

where

• V

(REF)

= 1.235 V typically

• K

(REF)

= 64, 128, 256, or 512 (default)

TPS929121-Q1

SLVSFZ4A – DECEMBER 2020 – REVISED FEBRUARY 2021

www.ti.com

16 Submit Document Feedback

Product Folder Links: TPS929121-Q1

The recommended resistor values of R

(REF)

and amplifier ratios of K

(REF)

are listed in Table 8-1.

Table 8-1. Reference Current Range Setting

CONF_REFRA

NGE

(REF)

FULL RANGE CURRENT (mA)

(REF)

= 8.45 kΩ R

(REF)

= 12.7 kΩ R

(REF)

= 31.6 kΩ

11b 512 75 50 20

10b 256 37.5 25 10

01b 128 18.75 12.5 5

00b 64 9.375 6.25 2.5

Place the R

(REF)

resistor as close as possible to the REF pin with an up to 2.2-nF ceramic capacitor in parallel to

improve the noise immunity. The off-board R

(REF)

setup is not allowed due to the concern of instability reference

current. TI recommends a 1-nF ceramic capacitor in parallel with R

(REF)

8.3.2.2 64-Step Programmable High-Side Constant-Current Output

TPS929121-Q1 has 12 channels of high-side current sources. Each channel has its own enable configuration

disables the channel output. To completely turn off the channel current, user can clear channel enable bit

CONF_ENCHx to 0. Upon power up, CONF_ENCHx is automatically reset to 0 to avoid unwanted blinking.

Each OUTx channel supports individual 64-step programmable current setting, also known as dot correction

(DC). The DC feature can be used to set binning values for output LEDs or to calibrate the LEDs to achieve high

brightness homogeneity based on external visual system to further save binning cost. The 6-bit register

CONF_IOUTx sets the current independently, where x is the channel number from 0 to 11. The OUTx current

can be calculated with Equation 2.

(OUTx) (FULL _RANGE)

(CONF _IOUTx 1)

I I



(2)

where

• CONF_IOUTx is programmable from 0 to 63.

• x is from 0 to 11 for different output channel.

• I

(FULL_RANGE)

can be calculated with Equation 1.

8.3.3 PWM Dimming

TPS929121-Q1 integrates independent 12-bit PWM generators for each OUTx channel. The current output for

each OUTx channel is turned on and off controlled by the integrated PWM generator. The average current of

each OUTx can be adjusted by PWM duty cycle independently, therefore, to control the brightness for LEDs in

each channel.

8.3.3.1 PWM Dimming Frequency

The frequency for PWM dimming is programmable by 4-bit register CONF_PWMFREQ with 16 options covering

from 200 Hz to 20.8 kHz. Select the frequency for PWM dimming based on the minimum brightness requirement

in application. TPS929121-Q1 supports down to 1-µs minimum pulse current for all 12-channel outputs.

8.3.3.2 PWM Generator

The 12-bit PWM generator constructs the cyclical PWM output based on a 12-bit digital binary input to control

the output current ON and OFF. Basically the PWM generator counts 256 pulses at base high frequency for

PWM output cycle period and counts number of pulses determined by MSB 8 bits of 12-bit binary input at the

same frequency for PWM ON period. The LSB 4 bits of 12-bit binary input is used to set up the dithering to

realize total 12-bit resolution. The base high frequency is generated by internal oscillator, which is 256 times of

the frequency programmable by CONF_PWMFREQ. Figure 8-2 is the signal path diagram for PWM generator.

www.ti.com

TPS929121-Q1

SLVSFZ4A – DECEMBER 2020 – REVISED FEBRUARY 2021

Submit Document Feedback

Product Folder Links: TPS929121-Q1

MUX

Exponential

CONF_PWMOUTx[7:0]

12-bit PWM

Generator

PWMOUT

CONF_PWMFREQ[3:0]

Internal Oscillator

MUX

ADDR2/CLK

ADDR1/PWM1

AND

NAND

CONF_ENCHx

x: 0~11

ADDR0/PWM0

NAND

CH5-CH0

CH11-CH6

CONF_PWMLOWOUTx[3:0]

Look-Up Table

Linear

CONF_EXTCLK

1: EXT CLK

0: INT CLK

EEP_INTADDR

1: INT ADDR

0: EXT ADDR

EEP_INTADDR

1: INT ADDR

0: EXT ADDR

CONF_EXPEN

1: LUT EN

0: LUT DIS

0h: 200Hz

1h: 250Hz

2h: 300Hz

3h: 350Hz

4h: 400Hz

5h: 500Hz

6h: 600Hz

7h: 800Hz

8h: 1000Hz

9h: 1200Hz

Ah: 2000Hz

Bh: 4000Hz

Ch: 5900Hz

Dh: 7800Hz

Eh: 9600Hz

Fh: 20800Hz

Figure 8-2. PWM Generator Path Diagram

8.3.3.3 Linear Brightness Control

When register CONF_EXPEN is set to 0, the MSB 8 bits of 12-bit binary input to PWM generator is directly

copied from 8-bit register CONF_PWMOUTx, and the LSB 4 bits is directly copied from 4-bit register

CONF_PWMLOWOUTx. The PWM output duty cycle can be calculated with Equation 3. Because the 4 LSB bits

inputs are used to control the dithering, setting CONF_PWMLOWOUTx to Fh disables the dithering if it is not

needed. The PWM output duty cycle is linearly controlled by the register CONF_PWMOUTx and

CONFPWMLOWOUTx, which provides the linearly brightness control to each channel output.

(OUTx)

(16 CONF_PWMOUTx+CONF_PWMLOWOUTx+1)

D 100%

4096

(3)

where

• CONF_PWWOUTx is decimal number from 0 to 255.

• CONF_PWMLOWOUTx is decimal number from 0 to 15.

• x is from 0 to 11 for different output channel.

If using the dithering feature to realize the 12-bit dimming resolution, set the PWM frequency higher than 2 kHz

through setting register CONF_PWMFREQ to avoid visible brightness flicker when the value of

CONF_PWMLOWOUTx is less than Fh. Higher PWM frequency can also prevent the visible LED flash in video

display due to the low beat frequency between digital camera shutter frequency and PWM frequency for LED

dimming.

Because the 12-bit PWM duty cycles require 2 bytes of write operation to update the completed data, the output

PWM duty cycle is not changed in between of the two bytes data transmission. TPS929121-Q1 only updates

PWM duty cycle of any output when its high 8-bit CONF_PWMOUTx is written. When very fast brightness

change is needed, for example, fade-in and fade-out effects, simultaneous PWM duty cycle change of all

TPS929121-Q1

SLVSFZ4A – DECEMBER 2020 – REVISED FEBRUARY 2021

www.ti.com

18 Submit Document Feedback

Product Folder Links: TPS929121-Q1

channels is required. Setting CONF_SHAREPWM to 1 enables all channels using the PWM dutycycle setting of

channel 0 to save communication latency.

8.3.3.4 Exponential Brightness Control

The TPS929121-Q1 can also generate PWM duty-cycle output following exponential curve. The integrated look-

up table provides a one-to-one conversion from 8-bit register CONF_PWMOUTx to 12-bit binary code following

exponential increment when register CONF_EXPEN is set to 1 as Figure 8-3 illustrated. When exponential

control path is selected, the CONF_PWMLOWOUTx data is neglected. By using the exponential brightness

control, LED brightness change by one LSB is invisible to human eyes especially at low brightness range.

8-Bit CONF_PWMOUTx[7:0]

12-Bit Lookup Table Output

0 32 64 96 128 160 192 224 256

512

1024

1536

2048

2560

3072

3584

4096

D100

Figure 8-3. PWM Duty Cycle vs 8-bit Code for Exponential Dimming

CONF_EXPEN bit selects the dimming method between linear or exponential. Setting the bit CONF_EXPEN to 1

enables the look-up table for exponential dimming curve. In exponential PWM dimming mode, 8-bit register

CONF_PWMOUTx is converted to 12-bit PWM dutycycle by look-up table automatically. Clear the bit

CONF_EXPEN to 0 disables the look-up table. In this case, users must provide 12-bit PWM duty cycle.

CONF_PWMOUTx stores the high 8-bit of 12-bit PWM duty-cycle information. CONF_PWMLOWOUTx stores

the low 4-bit.

To avoid visible brightness flicker for exponential dimming, choose PWM frequency higher than 2 kHz through

setting register CONF_PWMFREQ. Higher PWM frequency can also avoid the visible LED flash in video display

due to the low beat frequency between digital camera shutter frequency and PWM frequency for LED dimming.

During power-up or in fail-safe state, the registers CONF_EXPEN, CONF_PWMOUTx, CONF_PWMFREQ are

automatically reset to their default values stored in EEPROM register EEP_EXPEN, EEP_PWMOUTx,

EEP_PWMFREQ. CONF_PWMLOWOUTx is reset to Fh as default value.

In fail-safe state, PWM generator only uses 8-bit EEPROM data from EEP_PWMOUTx to build PWM dutycycle

output and ignores the low 4-bit. The PWM duty-cycle calculation is as shown in Equation 4.

(OUTx)

(EEP_PWMOUTx+1)

D 100%

256

(4)

where

• EEP_PWMOUTx is decimal number from 0 to 255.

• x is from 0 to 11 for different output channel.

www.ti.com

TPS929121-Q1

SLVSFZ4A – DECEMBER 2020 – REVISED FEBRUARY 2021

Submit Document Feedback

Product Folder Links: TPS929121-Q1

8.3.3.5 External Clock Input for PWM Generator (CLK)

The TPS929121-Q1 has internal precision oscillator for PWM generators. In addition, the device also supports

an external clock for the PWM generator source with ADDR2/CLK input considering the synchronization

requirement.

Then external clock inputs through ADDR2/CLK pin is a multi-function pin not only for external clock input but

also for device slave address selection. The device slave address stored in EEPROM must be enabled by

burning EEP_INTADDR to 1 to release ADDR2/CLK pin for external clock input. In addition, register

CONF_EXTCLK can be used to choose the PWM generator between external input or an internal oscillator.

Writing CONF_EXTCLK to 1 enables the external clock source. The external clock frequency must be 256 times

of desired PWM dimming frequency. The external clock source is only used in PWM generation. TI recommends

that the external clock frequency be less than 1 MHz. The internal clock is recommended when high dimming

frequency is required.

8.3.3.6 External PWM Input ( PWM0 and PWM1)

The TPS929121-Q1 has two PWM inputs that can be used to directly control OUT0-11. The both ADDR1/

PWM1 and ADDR0/ PWM0 pins are multi-function pins for not only external PWM input signal but also device

slave address selection pins. The register EEP_INTADDR must be written to 1 to release both twos for external

PWM input. When the EEP_INTADDR is 1, the ADDR0/ PWM0 is functional as external active low PWM control

input for OUT0-5 and the ADDR1/ PWM1 is functional as external active low PWM control input for OUT6-11, as

shown in Figure 8-2. Setting the register CONF_PWMOUTx to 0xFF and the register CONF_PWMLOWOUTx to

0xF is recommended when external PWM input is used. In case external PWM is not used, ADDR0/ PWM0 and

ADDR1/ PWM1 must be tied to GND when EEP_INTADDR is set to 1.

8.3.4 On-chip 8-bit Analog-to-Digital Converter (ADC)

The TPS929121-Q1 has integrated a successive-approximation-register (SAR) ADC for diagnostics. It routinely

monitors supply voltage if the ADC is idle and stores SUPPLY conversion results into ADC_SUPPLY.

To manually read the voltage of an ADC channel as listed in Table 8-2, user must write the 5-bit register

CONF_ADCCH to select channel. Once CONF_ADCCH register is written, the one time ADC conversion starts

and clears FLAG_ADCDONE register. As long as the ADC conversion is completed, the ADC result is available

in 8-bit register ADC_OUT and sets FLAG_ADCDONE to 1. Reading the ADC_OUT register also clears

FLAG_ADCDONE, and the FLAG_ADCDONE is set to 0 after reading completion.

Because the TPS929121-Q1 supports PWM control for adjusting LED brightness, the voltage on OUT0 to

OUT11 is like a pulse waveform. When the current output is enabled by setting CONF_ENCHx to 1, the ADC

measures the voltage on assigned OUTx after the channel is turned on with t

(diag_pulse)

delay time, which is

programmable by 4-bit register CONF_ODPW. When the channel is disabled by setting CONF_ENCHx to 0, the

ADC samples the voltage on assigned OUTx at off state.

The analog value can be calculated based on the read back binary code with Equation 5 and Table 8-2.

 

AnalogValue a k ADC_ OUT  u

(5)

where

• ADC_OUT is decimal number from 0 to 255.

TPS929121-Q1

SLVSFZ4A – DECEMBER 2020 – REVISED FEBRUARY 2021

www.ti.com

20 Submit Document Feedback

Product Folder Links: TPS929121-Q1

剩余167页未读，继续阅读

不觉明了

粉丝: 3738
资源: 5759

TI TPS929121-Q1：12通道汽车级高侧LED驱动器

TI-TPS92663A-Q1.pdf

stays mad 反PCL宣传库。Anti PCL pro.zip

伊犁师范大学在四川2020-2024各专业最低录取分数及位次表.pdf

yolo算法-植物数据集-1417张图像带标签adamweeds.zip

clickhouse-jdbc驱动jar文件用于建立jdbc链接

辽宁何氏医学院在四川2020-2024各专业最低录取分数及位次表.pdf

泰尔指数、泰尔指数模型（含案例源码+数据+stata详细操作过程）-最新出炉.zip

springboot124中药实验管理系统设计与实现.zip

比赛地址：中文NLP地址要素解析 方案：BERT-BiLSTM-CRF-NER

基于pytorch卷积神经网络的中文手写汉字识别，使用HWDB数据库_hand-writing-recognition.zip

最新资源

比赛地址：中文NLP地址要素解析方案：BERT-BiLSTM-CRF-NER