SNVSA15B Data sheet | 德州仪器 TI.com.cn

SNVSA15B December 2013 – December 2015 LP8557

PRODUCTION DATA.

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机械数据 (封装 | 引脚)

YFQ|16
- MXBG172

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7 Specifications

7.1 Absolute Maximum Ratings

Over operating free-air temperature range (unless otherwise noted) ⁽¹⁾⁽²⁾

		MIN	MAX	UNIT
V_DD	Voltage range on VDD pin	–0.3	6	V
V_IO	Voltage range on digital IO pins	–0.3	6	V
V_O	Voltage range on SW, FB, LED1 to LED6 pins	–0.3	31	V
T_J	Junction temperature	–30	125	°C
T_sldr	Maximum lead temperature (soldering)		260	°C
T_stg	Storage temperature range	–65	150	°C

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) All voltage values are with respect to the potential at the GND pin.

7.2 ESD Ratings

			VALUE	UNIT
V_(ESD)	Electrostatic discharge	Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001⁽¹⁾	±2000	V
V_(ESD)	Electrostatic discharge	Charged-device model (CDM), per JEDEC specification JESD22-C101⁽²⁾	±500	V

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions

Over operating free-air temperature range (unless otherwise noted) ⁽¹⁾⁽²⁾

	MIN	MAX	UNIT
V_DD	2.7	5.5	V
V (SW, FB, LED1 to LED6)	0	28	V
Ambient temperature, T_A	–30	85	°C
Junction temperature, T_J	–30	125	°C

(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability

(2) All voltage values are with respect to the potential at the GND pin.

7.4 Thermal Information

THERMAL METRIC⁽¹⁾⁽²⁾		LP8557/LP8557I	UNIT
		YFQ (DSBGA)
		16 PINS
R_θJA	Junction-to-ambient thermal resistance	75.7	°C/W
R_θJC(top)	Junction-to-case (top) thermal resistance	0.5	°C/W
R_θJB	Junction-to-board thermal resistance	16.2	°C/W
ψ_JT	Junction-to-top characterization parameter	0.2	°C/W
ψ_JB	Junction-to-board characterization parameter	16.2	°C/W

(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

(2) Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists, special care must be paid to thermal dissipation issues in board design.

7.5 Electrical Characteristics

Unless otherwise specified: T_A = 25°C, V_DD = 3.8 V.

PARAMETER		TEST CONDITIONS	MIN	TYP	MAX	UNIT
V_DD	Input voltage range		2.7		5.5	V
I_DDQ	Standby current				1	µA
I_DD	Operating current	No current going through LEDs		2.2		mA
ƒ_OSC	Internal oscillator frequency accuracy		–4% –7%⁽¹⁾		4% 7%⁽¹⁾
T_TSD	Thermal shutdown threshold⁽³⁾			150		°C
T_{TSD_hyst}	Thermal shutdown hysteresis⁽³⁾			20		°C

(1) Limits apply over the full operating ambient temperature range –30°C ≤ T_A ≤ 85°C.

7.6 Boost Converter Electrical Characteristics

Unless otherwise specified: T_A = 25°C, V_DD = 3.8 V⁽¹⁾.

PARAMETER		TEST CONDITIONS	MIN	TYP	MAX	UNIT
R_{DS_ON}	Switch ON resistance	I_SW = 0.5 A		0.2		Ω
V_{BOOST_MIN}	Minimum output voltage		6⁽²⁾	7	8⁽²⁾	V
V_{BOOST_MAX}	Maximum output voltage		27⁽²⁾	28	29⁽²⁾	V
I_{SW_CL}	SW pin current limit		2.1	2.4	2.5	A
I_{LOAD_MAX}	Maximum continuous load current ⁽³⁾	I_{SW_LIM} = 2.4 A V_IN = 3 V, V_OUT = 24 V		160		mA
ƒ_SW	Switching frequency			500 1000		kHz
V_{OVP_TH}	Overvoltage protection voltage threshold			V_{BOOST_MAX} + 1.6		V
V_{UVLO_TH}	UVLO threshold			2.5		V
V_{UVLO_hyst}	UVLO hysteresis			50		mV
t_PULSE	Switch pulse minimum width ⁽³⁾	No load		80		ns
t_STARTUP	Boost start-up time ⁽³⁾			1		ms

(1) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis.

(2) Limits apply over the full operating ambient temperature range –30°C ≤ T_A ≤ 85°C.

(3) Verified by design and not tested in production.

7.7 LED Driver Electrical Characteristics (LED1 To LED6 Pins)

Unless otherwise specified: T_A = 25°C, V_DD = 3.8 V⁽¹⁾.

PARAMETER		TEST CONDITIONS	MIN	TYP	MAX	UNIT
I_LEAKAGE	Leakage current	Outputs LED1...LED6, V_OUT = 28 V			1	µA
I_{LED_MAX}	Maximum sink current LED1...6			25		mA
I_{LED_ACC}	LED current accuracy⁽²⁾	Output current set to 20 mA	–3% –4%⁽³⁾		3% 4%⁽³⁾
I_MATCH	Channel to Channel Matching ⁽²⁾	Output current set to 20 mA		0.5
ƒ_LED	LED switching frequency⁽³⁾	PFREQ = 000b PFREQ = 111b		4.9 39.1		kHz
V_SAT	Saturation voltage⁽⁴⁾	Output current set to 20 mA		200		mV

(1) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis.

(2) The LED current accuracy is defined as 100 × (ILED_AVE – ILED_Target) / ILED_AVE. The channel-to-channel LED current matching is defined as (ILED_MAX – ILED_MIN) / ILED_AVE.

(3) Limits apply over the full operating ambient temperature range –30°C ≤ T_A ≤ 85°C.

(4) Saturation voltage is defined as the voltage when the LED current has dropped 10% from the value measured at 1 V.

7.8 PWM Interface Characteristics (PWM Pin)

See ⁽¹⁾

PARAMETER		TEST CONDITIONS	MIN	TYP	MAX	UNIT
ƒ_PWM	PWM frequency⁽²⁾		75		25000	Hz
t_{MIN_ON}	Minimum pulse ON time⁽²⁾			1		µs
t_{MIN_OFF}	Minimum pulse OFF time⁽²⁾			1		µs
t_ON	Turnon delay from standby to backlight on⁽²⁾	PWM pin goes from low to switching.		9		ms
t_STBY	Turnoff delay from backlight off to standby⁽²⁾	PWM pin goes from switching to low.		52		ms
PWM_RES	PWM input resolution⁽²⁾	ƒ_IN < 2.4 kHz		12		bits
		ƒ_IN < 4.8 kHz		11
		ƒ_IN < 9.6 kHz		10
		ƒ_IN < 19.5 kHz		9
		ƒ_IN < 25 kHz		8

(1) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis.

(2) Verified by design and not tested in production.

7.9 Logic Interface Characteristics
(PWM, FSET/SDA, ISET/SCL Pins)

Limits apply over the full operating ambient temperature range –30°C ≤ T_A ≤ 85°C⁽¹⁾.

PARAMETER		TEST CONDITIONS	MIN	MAX	UNIT
V_IL	Input low level			0.4	V
V_IH	Input high level		1.44		V
I_I	Input current		–1	1	µA
V_OL	Output low level	I_SDA = 3 mA		0.5	V
I_O	Output leakage	V_SDA = 2.8 V		1	µA

(1) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis.

7.10 I²C Serial Bus Timing Parameters (SDA, SCL)

See⁽¹⁾ and Figure 1.

PARAMETER		MIN	MAX	UNIT
ƒ_SCL	Clock Frequency		400	kHz
1	Hold Time (repeated) START Condition	0.6		μs
2	Clock Low Time	1.3		μs
3	Clock High Time	600		ns
4	Setup Time for a Repeated START Condition	600		ns
5	Data Hold Time	50		ns
6	Data Setup Time	100		ns
7	Rise Time of SDA and SCL	20 + 0.1C_b	300	ns
8	Fall Time of SDA and SCL	15 + 0.1C_b	300	ns
9	Set-up Time for STOP condition	600		ns
10	Bus Free Time between a STOP and a START Condition	1.3		μs
C_b	Capacitive Load Parameter for Each Bus Line Load of 1 pF corresponds to 1 ns.	10	200	ns
t_WAIT	Wait time from V_DD = 2.7 V to 1^st I²C command	150		μs

(1) Verified by design and not tested in production.

Figure 1. I²C-Compatible Timing

7.11 Typical Characteristics

Unless otherwise specified: V_IN = V_DD = 3.8 V, L = 10 µH Cyntec PIME051E, D = Diodes PD3S130L-7, C_OUT = 2 × 4.7 µF, LED V_ƒ = 2.85 V (typical), I_{LED_MAX} = 25 mA per string.