ST STCF04 User Manual

STCF04

High power white LED SuperCap™ driver with I²C interface

Features

■Buck-boost converter with 1.5 A peak current limiting and synchronous rectification

■Burst mode operation when output is charged

■Input voltage range 2.5 V to 5.5 V

■Programmable output charging voltage up to 5.5 V

■Full I²C control

■Operation modes:

– Shutdown mode

– Monitoring mode with NTC and SuperCap monitoring

– Idle mode

– Flash mode

– Torch mode: up to 320 mA

■Controlled LED current in all modes

■Soft and hard triggering of Flash, Torch and Picture light modes

■Torch dimming in 12 exponential steps

■Flash dimming in 8 steps

■Active balancing of SuperCap voltage

■SuperCap status flag

■Internally or externally timed flash operation

■Digitally programmable safety timeout in Flash mode

■Torch mode safety timeout

■LED overtemperature detection and protection with external NTC resistor

■Shorted LED failure detection and protection

■Chip overtemperature detection and protection

Datasheet − production data

TFBGA25 (3 x 3 mm)

Applications

■Cell phones and smartphones

■Camera flashes/strobe

■PDAs and digital still cameras

Description

The STCF04 is a dedicated and space optimized high efficiency solution for driving a flash LED module in cameras, phones, PDAs and other handheld devices using the SuperCap technology. It is based on a DC-DC buck-boost converter, which ensures a proper and efficient charging control and monitoring of the SuperCap in the whole battery voltage range. The output current control ensures a good current regulation over the forward voltage spread characteristics of the flash LEDs in Torch and Flash mode operation. The SuperCap charging current is limited to a defined value which avoids overload of the battery. The SuperCap discharge current flows through the LEDs and the external MOSFET which must be chosen according to the desired flash current.

Table 1.	Device summary
	Order code	Package	Packaging
	STCF04TBR	TFBGA25 (3 x 3 mm)	3000 parts per reel
May 2012		Doc ID 022927 Rev 2	1/43

This is information on a product in full production.

www.st.com

Contents	STCF04

Contents

1	Description (continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 5
2	Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		6
3	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
4	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		8
5	Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		9
6	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		11
7	Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		14
8	Detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		15
	8.1	Logic pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15

8.1.1 SCL, SDA pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.2 FLASH pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.3 TORCH pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.4 RESET pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.5 ATN pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.6 ADD pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8.1.7 READY pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8.1.8 Data validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 8.1.9 START and STOP conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 8.1.10 Byte format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 8.1.11 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 8.1.12 Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 8.1.13 Writing to a single register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 8.1.14 Writing to multiple registers with incremental addressing . . . . . . . . . . . 20 8.1.15 Reading from a single register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.1.16 Reading from multiple registers with incremental addressing . . . . . . . . 21

9	Description of the internal registers . . . . . . . . . . . . . . . . . . . . . . . . . . .	22
	9.1 Commands (CMD_REG) 00(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	22

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STCF04	Contents

9.1.1 PWR_ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1.2 FLASH_ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1.3 TCH_ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.1.4 NTC_ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.1.5 TCHV_H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.1.6 CHRG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.1.7 MONTR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9.2 Flash register (FL_REG) 01(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.3 AUX LED (AUX_REG) 02(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 9.4 Status (STAT_REG) 03(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9.5 Feature (FTR_REG) 04(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 9.6 Torch register (TRCH_REG) 05(hex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

10	Theory of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		28
	10.1	The state machine diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	28
	10.2	Power-ON reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29

10.2.1 RESET pin function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

10.3 Shutdown mode and NTC mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 10.4 Monitoring mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 10.5 Idle mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 10.6 AUX LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

10.7Single or multiple flash using external (microprocessor) temporization . . 30

10.8 External (microprocessor) temporization using the FLASH_ON bit . . . . . 31 10.9 Single flash using internal temporization . . . . . . . . . . . . . . . . . . . . . . . . . 31 10.10 Light sensor feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

11	Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . .	32
12	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	38
13	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42

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List of tables	STCF04

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 3. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 5. List of external components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 6. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 7. I²C address table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 8. Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Table 9. I²C register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 10. Command register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 11. Flash register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 12. Flash mode dimming registers settings (EXT_REG = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 13. Flash time dimming register settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 14. AUX LED register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 15. Auxiliary LED dimming table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 16. Auxiliary LED timing table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 17. Status register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 18. Status register details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 19. Feature register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 20. Light sensor reference dimming register settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 21. DC-DC converter output voltages (VOUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 22. DC-DC converter coil peak current limit values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 23. Torch register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 24. Torch mode dimming registers settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 25. The safety timeout for Torch mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 26. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

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STCF04	List of figures

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 2. Pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 3. Application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 4. Behavior of the READY pin in different modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 5. Data validity on the I²C bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 6. Timing diagram on I²C bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 7. Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 8. Acknowledge on I²C bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 9. Writing to a single register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 10. Writing to multiple registers with incremental addressing. . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 11. Reading from a single register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 12. Reading from multiple registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 13. State machine diagram of the STCF04 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Figure 14. Reset timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 15. Flash current vs. input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Figure 16. Torch current vs. input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Figure 17. Aux LED current vs. input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 18. Charging efficiency vs. VOUT voltage (VIN = 3.6 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Figure 19. Torch time - settings compared to real values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 20. Torch current - settings compared to real values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 21. Flash time - settings compared to real values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 22. Flash current - settings compared to real values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 23. Aux LED time - settings compared to real values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 24. Aux LED currentsettings compared to real values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 25. Operation in Flash mode - single flash pulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 26. Operation in Flash mode - multiple flash pulses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 27. Operation in Torch mode with TCHV_H bit = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Figure 28. Operation in Torch mode with TCHV_H bit = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

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Description (continued)	STCF04

1 Description (continued)

All the functions of the device are controlled through the I²C bus which reduces the number of logic pins of the package and saves PCB tracks on the application board. Hard and softtriggering of flash and torch are both supported. The device includes many functions to protect the chip and the power LEDs. These include a soft-start control, chip overtemperature detection and protection, and shorted LED detection and protection. In addition, a digital programmable timeout function protects the LEDs in case of a wrong command issued by the microprocessor. An optional external NTC is supported to protect the LEDs against overheating. It is possible to separately program the current intensity in Flash and Torch mode through I²C. In order to guarantee the proper function of Flash mode, the SuperCap voltage should be monitored by the microprocessor using the READY pin feature. In case of insufficient power from the SuperCap, a warning is generated. The device is packaged in BGA 3 x 3 mm with 1 mm height.

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STCF04	Diagram

2 Diagram

Figure 1. Block diagram

	VBAT		LSCON	LSIN	PVBAT	VLX1	VLX2
										VOUT
		PREREG			BUCK		BOOST
AUXLED	AUXLED	& BIAS			CONVERTER		CONVERTER
								SUPERCAP		VMID
								BALANCING &
								SUPERCAP	REF
								VOLTAGE
								BALANCING &	120 mV..1.2 V
READY								CONTROL
								VOLTAGE
								CONTROL
					FLASH
					FLASH
TORCH					TRIGGERING				MX
					TRIGGERING					DRIVE
					&CURRENT
					&CURRENT
		CONTROL			LIMITITING
					LIMITITING
FLASH			NTC_ON
		LOGIC								LED
ATN							TORCH
							TORCH
							DIMMING
RESET					OSCILLATOR & TIME		DIMMING
					COUNTER		+			PGND
							-
								CURRENT
							NTC_W
								SENSING
										ISENS
							REF4		MX
SCL					PROTECTIONS &			NTC_ON
					DIAGNOSTICS
						LED	+
						FAIL	-
SDA		I²C					REF5
							NTC_H
		INTERF
ADD					ON - CHIP	OVER -		NTC	ENABLE/
					TEMP	CURRENT		BIAS	1.8 V REF
					PGND	AGND	RX	NTC

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Pin configuration	STCF04

3 Pin configuration

Figure 2. Pin connection (top view)

Table 2.	Pin description
Pin		Symbol	Description
A1		VLX1	Inductor connection 1
E1		VLX2	Inductor connection 2
D5		RX	RX resistor connection
D1		VOUT	SuperCap connection
C1		VMID	SuperCap middle pin connection
E5		NTC	NTC resistor connection
A3		READY	SuperCap status flag pin
B3		SCL	I²C clock signal
A4		FLASH	Flash trigger input
E2		AGND	Signal ground
B5		TORCH	Torch trigger input
B4		RESET	External reset input
D4		ISENS	Flash regulator sensing connection
C3		ADD	I²C address selection
E4		LED	Diode module cathode connection
C4		ATN	Attention (open drain output, active LOW)
B1		PVBAT	Supply voltage
A5		SDA	I²C data
E3		AUXLED	Auxiliary red LED connection
B2		LSCON	Light sensor capacitor connection
D3		VBAT	Signal supply voltage
A2		LSIN	Light sensor input
C5		DRIVE	MOSFET driver output
C2, D2		PGND	Power ground + die back connection

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STCF04	Maximum ratings

4 Maximum ratings

Table 3.	Absolute maximum ratings
Symbol				Parameter			Value		Unit
VBAT, PVBAT				Signal supply voltage			- 0.3 to 6		V
	VLX			Inductor connection			- 0.3 to 6		V
	VOUT			SuperCap connection			- 0.3 to 6		V
VDCDC				DC-DC converter output			- 0.3 to 6		V
	VMID			SuperCap middle pin connection			- 0.3 to 6		V
AUXLED				AUXLED connection			- 0.3 to 6		V
	LED			LED connection			- 0.3 to 6		V
SCL, SDA, ATN, ADD,
READY, TORCH,				Logic pins		- 0.3 to VBAT + 0.3			V
FLASH, RESET
PVBAT				Power supply voltage		- 0.3 to VBAT + 0.3			V
DRIVE				External MOSFET drive			- 0.3 to 6		V
	LSIN			Light sensor input			- 0.3 to 6		V
LSCON				Light sensor capacitor connection			- 0.3 to 6		V
	RX			Connection for reference resistor			- 0.3 to 3		V
	NTC			Connection for LED temperature sensing			- 0.3 to 3		V
ISENS				Flash regulator sensing connection			- 0.3 to 3		V
	ESD			Human body model		± 2			kV
	PTOT			Continuous power dissipation (at TA=70 °C)		1			W
	TOP			Operating junction temperature range			- 40 to 85		°C
	TJ			Junction temperature			- 40 to 150		°C
	TSTG			Storage temperature range			- 65 to 150		°C
Note:	Absolute maximum ratings are those values beyond which damage to the device may occur.
	Functional operation under these conditions is not implied.
Table 4.	Thermal data
Symbol				Parameter			Value		Unit
R			Thermal resistance junction-ambient (1)				56		°C/W
thJA

1. This parameter corresponds to the PCB board, 8 layers with 1 inch² of cooling area.

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Application	STCF04

5 Application

Figure 3. Application schematic

Note:	**: connect to VI, or GND or SDA or SCL to choose one of the 4 different I²C slave
	addresses. Optional components to support auxiliary functions are highlighted with blue
	rectangles.
Note:	The anode of the AuxLED should be also connected to the VOUT.

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STCF04						Application
Table 5.	List of external components
Component		Manufacturer		Part number	Value	Size
L		Murata		LQM2HPN1R0MJC	1 µH / 1.5 A	2.5 x 2.0 x 1.1 mm
		TDK		VLS252012T-1R0N1R7	1 µH / 1.7 A	2.5 x 2.0 x 1.2 mm
CIN, COUT		TDK		C1608X5R0J106MT	10 µF / 6.3 V	0603
Rx		Rohm		MCR01MZPJ15K	15 kΩ	0402
NTC		Murata		NCP21WF104J03RA	100 kΩ	0805
		Murata		DME2W5R5K404M	400 mF / 5.5 V	20.5 x 18.5 x 3 mm
CSUP		TDK		EDLC152344	550 mF / 5.5 V	44 x 23 x 1.5 mm
				EDLC272020	500 mF / 5.5 V	20 x 20 x 2.7 mm
		CAP-xx		GS 2 19F	1.6 F / 5 V	40 x 17 mm
LED MODULE		Luxeon		4x LXCL-PWF4	White LED	0805
TFL		STMicroelectronics		STL8NH3LL	8 A / 12 kΩ	3.3 x 3.3 x 0.9 mm
RFL		Tyco		TL2BR01FTE	0R01	1206
(1)		TDK			10 µF / 6.3 V	0402
CINT
RLIGHT*		Tyco				0402
TFOTO*		Vishay		TEMT6000		4 x 2 x 1 mm
AUXLED					Red LED	0603
CR					100 nF	0402

1. Optional components for the auxiliary light sensor feature.

Note:	The components listed above refer to a typical application. However, STCF04 operation is
	not limited to the choice of these external components.

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Electrical characteristics	STCF04

6 Electrical characteristics

TA = 25 °C, VIN = 3.6 V connected to VBAT and PVBAT, CIN = 10 µF, CSUP = 1.6F/5 V L = 1 µH, RX = 15 kΩ, VFLED = 4.2 V/10 A. Unless otherwise specified, typical values are at 25 °C.

	Table 6.	Electrical characteristics
	Symbol	Parameter	Test conditions	Min.	Typ.	Max.	Unit
	VIN	Operating input supply		2.5		5.5	V
		voltage
	VPW_ON	Power-ON reset	VIN rising		2.3		V
	RESET	threshold
		Output current
		adjustment range	Torch mode VIN=2.7 V to 5.5 V	15		320
	IO	ITORCH					mA
		Auxiliary LED output
		current adjustment	Idle mode, VI or VO=3.3 V to 5.5 V	0		100
		range IAUXLED
	VISENS	Current sensing input	VIN=2.7 V to 5.5 V, ILED = 12 A	108	120	132	mV
			RFL = 10 mΩ
	IPEAK	Switch peak current limit	VIN=2.7 V to 5.5 V, IDC0=0		1.45		A
			VIN=2.7 V to 5.5 V, IDC0=1		1.80
		Regulated voltage
		range optimized for	VIN=2.7 V to 5.5 V	4.5		5.5	V
		Flash mode
	VOUT	Regulated voltage			VFLED+
		range optimized for	VIN=2.7 V to 5.5 V				V
					0.25
		Torch mode
		VOUT tolerance	Percentage with respect to	-5		+5	%
			programmed voltage
	IMID	Active balancing output	VIN=2.7 V to 5.5 V	-400		400	mA
	IO	Output current variation	Torch mode ILED = 300 mA	-10		10	%
		Quiescent current in	VIN=2.7 to 5.5 V, NTC_ON=0			1
		Shutdown mode
		Quiescent current in	VIN=2.7 to 5.5 V, NTC_ON=1		2		µA
	IQ	Shutdown mode
		Quiescent current in	NTC_ON=0, SuperCap monitoring=1		45
		Monitoring mode
		Quiescent current in Idle	NTC_ON, CHRG=0			1	mA
		mode
	fs	Switching frequency	VIN=2.7 V		1.8		MHz

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Doc ID 022927 Rev 2

STCF04						Electrical characteristics
Table 6.	Electrical characteristics (continued)
Symbol	Parameter			Test conditions		Min.	Typ.	Max.	Unit
	Efficiency of the	VIN=3.7 V, VDC_0,1=1, IDC0=1					85
	converter
ν		VIN=2.7 V to 4.2 V, IDC_0=1,					50		%
	Efficiency in Torch mode	TCHV_H=1 ITORCH=320 mA
	operation	VIN=2.7 V to 4.2 V, IDC_0=1,					70
		TCHV_H=0 ITORCH=320 mA
		VSUPMAX=5.5 V, VSUPMIN=5.5 V-
		VSUPHYST, TCHV_H=1 or					1.3
		FLASH_ON=1
		VSUPMAX=5.0 V, VSUPMIN=5.0 V-
	SuperCap regulated	VSUPHYST, TCHV_H=1 or					0.8
VSUPHYST		FLASH_ON=1							V
	voltage hysteresis
		VSUPMAX=4.5 V, VSUPMIN=4.5 V-
		VSUPHYST, TCHV_H=1 or					0.3
		FLASH_ON=1
		VSUPMAX=4.2 V, VSUPMIN=4.2 V-					0.2
		VSUPHYST, TCHV_H=0
VMONIREADY	SuperCap voltage ready	PWR_ON=0, VDC_0 or/and VDC_1=1					0.2		V
	hysteresis
OTP	Overtemperature	VIN=5.5 V					140		C
	protection
OTHYST	Overtemperature	VIN=5.5 V					20		C
	hysteresis
V_NTCW	NTC threshold warning	Idle mode, INTC=2 mA max.					0.56		V
V_NTCH	NTC threshold hot	Idle mode, INTC=2 mA max.					1.2		V
VOL	Output logic signal level	I	ATN, READY	=+10 mA				0.3	V
	low ATN, READY
IOZ	Output logic leakage	VATN, READY =3.3 V						1	mA
	current ATN, READY
VIL	Input logic signal level					0		0.4
	SCL, SDA, TEST,
		VIN=2.7 V to 5.5 V							V
VIH	RESET, SCHRG,					1.4		3.0
	FLASH, TORCH, ADD
ILSCON	Input reset current	VIN=2.7 V to 5.5 V, VREF=1.6 V						10	mA
VLSIN	Analog input signal	VIN=2.7 V to 5.5 V				0.1		1.6	V
	range
	MOSFET driver output	Source: IDRIVE = -8 mA					4.27		V
VDRIVE		Sink: IDRIVE = +8 mA					1.05		V
	Reference voltage	EXT_REG=1 (1)				0.12		1.2	V
	range
TON	LED current rise time	Flash triggered by external trig						0.3	ms
	ILED=0 to ILED=max.

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