SLUSCZ1
May 2017
TPS92518-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Schematic
4
Revision History
5
Pin Configuration and Functions
Pin Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Typical Characteristics
7
Parameter Measurement Information
7.1
CSN Pin Falling Delay (tDEL)
7.2
Off-Timer (tOFF)
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
General Operation
8.3.1.1
Constant Off-Time vs. Constant µs×V operation
8.3.1.2
Output Equation
8.3.1.3
OFF Timer
8.3.1.3.1
Off-time and Maximum Off-time Calculations
8.3.2
Important System Considerations: Off-Timer and Maximum Peak Threshold Values
8.3.2.1
Peak Current Sense Comparator
8.3.2.2
Peak Current Threshold - LEDx _PKTH_DAC
8.3.2.3
Off-Time Thresholds - LEDx_TOFF_DAC and LEDx_MAXOFF_DAC
8.3.3
Shunt FET or Matrix dimming: Maximum Off-timer Calculation
8.3.3.1
Output Ringing and TPS92518-Q1 Protection
8.3.3.2
Live Peak and Off-Time Threshold Changes
8.3.4
VIN and the VCC Internal Regulators
8.3.5
Output Enable Control Logic
8.3.5.1
EN/UV2 - SPI Control Bypass
8.3.6
BOOT Capacitor and BOOT UVLO
8.3.7
Drop-out Operation
8.3.7.1
Early Drop-Out (Boot Capacitor Voltage >> VBOOT-UVLO)
8.3.7.2
Full Drop-Out (Boot Capacitor Voltage reaching VBOOT-UVLO)
8.3.7.3
Minimum BOOT Voltage and FET Control
8.3.7.4
BOOT Controlled internal Pull-Down
8.3.8
Analog and PWM Dimming
8.3.8.1
Dimming Methods
8.3.8.2
PWMx Pin Operation
8.3.8.3
PWM Dimming - Current Rise Performance
8.3.8.4
PWM and Analog Dimming - Linearity Limitations and Buck Converters
8.3.8.4.1
PWM:
8.3.8.4.2
ANALOG:
8.3.8.5
DCM Current Calculation
8.3.8.6
Current Sharing
8.3.9
VIN and CSPx Pin Configuration
8.3.10
Enable and Undervoltage Lock-out Configuration
8.3.11
Voltage Sampling and DAC Operation
8.3.11.1
ADC Control and LED Voltage Updating
8.3.12
Device Functional Modes
8.3.12.1
Analog Dimming
8.3.12.2
PWM Dimming
8.4
Serial Interface
8.4.1
Command Frame
8.4.2
Response Frame Formats
8.4.2.1
Read Response Frame Format
8.4.2.2
Write Response Frame Format
8.4.2.3
Write Error/POR Frame Format
8.4.2.4
SPI Error
8.5
Registers
8.5.1
CONTROL Register (Address = 00h) [reset = 00h]
Table 3.
CONTROL Register Field Descriptions
8.5.2
STATUS (FAULT) Register (Address = 01h) [reset = 10h]
Table 4.
STATUS Register Field Descriptions
8.5.3
THERM_WARN_LMT Register (Address = 02h) [reset = 80h]
Table 5.
THERM_WARN_LMT Register Field Descriptions
8.5.4
LED1_PKTH_DAC Register (Address = 03h) [reset = 80h]
Table 6.
LED1_PKTH_DAC Register Field Descriptions
8.5.5
LED2_PKTH_DAC Register (Address = 04h) [reset = 80h]
Table 7.
LED2_PKTH_DAC Register Field Descriptions
8.5.6
LED1_TOFF_DAC Register (Address = 05h) [reset = 80h]
Table 8.
LED1_TOFF_DAC Register Field Descriptions
8.5.7
LED2_TOFF_DAC Register (Address = 06h) [reset = 80h]
Table 9.
LED2_TOFF_DAC Register Field Descriptions
8.5.8
LED1_MAXOFF_DAC Register (Address = 07h) [reset = 80h]
Table 10.
LED1_MAXOFF_DAC Register Field Descriptions
8.5.9
LED2_MAXOFF_DAC Register (Address = 08h) [reset = 80h]
Table 11.
LED2_MAXOFF_DAC Register Field Descriptions
8.5.10
VTHERM Register (Address = 09h) [reset = 0h]
Table 12.
VTHERM Register Field Descriptions
8.5.11
LED1_MOST_RECENT Register (Address = 0Ah) [reset = 0h]
Table 13.
LED1_MOST_RECENT Register Field Descriptions
8.5.12
LED1_LAST_ON Register (Address = 0Bh) [reset = 0h]
Table 14.
LED1_LAST_ON Register Field Descriptions
8.5.13
LED1_LAST_OFF Register (Address = 0Ch) [reset = 0h]
Table 15.
LED1_LAST_OFF Register Field Descriptions
8.5.14
LED2_MOST_RECENT Register (Address = 0Dh) [reset = 0h]
Table 16.
LED2_MOST_RECENT Register Field Descriptions
8.5.15
LED2_LAST_ON Register (Address = 0Eh) [reset = 0h]
Table 17.
LED2_LAST_ON Register Field Descriptions
8.5.16
LED2_LAST_OFF Register (Address = 0Fh) [reset = 0h]
Table 18.
LED2_LAST_OFF Register Field Descriptions
8.5.17
Reset Register (Address = 10h) [reset = 0h]
Table 19.
Reset Register Field Descriptions
8.6
Programming
8.6.1
TPS92518-Q1 Register Typedef - Sample Code
8.6.2
Command Frame - Sample Code
8.6.3
SPI Read/Write - Sample Code
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.2
Detailed Design Procedure
9.2.3
Application Curves
9.3
Dos and Don'ts
10
Power Supply Recommendations
10.1
Input Source Direct from Battery
10.2
Input Source from a Boost Stage
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
Device and Documentation Support
12.1
Receiving Notification of Documentation Updates
12.2
Community Resources
12.3
Trademarks
12.4
Electrostatic Discharge Caution
12.5
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|24
MPDS372A
Thermal pad, mechanical data (Package|Pins)
PWP|24
PPTD111R
Orderable Information
sluscz1_oa
sluscz1_pm
11
Layout