LM5155DSST

Part: LM5155 / LM51551 (LM5155x), Texas Instruments

Type: Nonsynchronous Boost, SEPIC and Flyback Controller (peak current mode)

Description: 3.5–45 V operating input (2.97–16 V when BIAS = VCC) nonsynchronous boost/SEPIC/flyback controller with up to 2.2 MHz switching frequency, 1.5 A peak gate driver and ±1% feedback reference.

Operating Conditions:

• BIAS supply voltage: 2.97–45 V
• VCC voltage: 2.97–16 V
• Operating junction temperature: -40 to 125 °C
• Switching frequency: 100 kHz to 2200 kHz

Absolute Maximum Ratings:

• BIAS to AGND: -0.3 to 50 V
• VCC to AGND: -0.3 to 18 V (or VBIAS + 0.3 V, whichever is lower)
• PGOOD to AGND: -0.3 to 18 V
• Junction temperature: -40 to 150 °C
• Storage temperature: -55 to 150 °C

Key Specs:

• Shutdown current (VBIAS = 12 V, VUVLO = 0 V): 2.6 μA typ, 5 μA max
• Operating current (VBIAS = 12 V, VUVLO = 2 V, RT = 220 kΩ): 480 μA typ, 540 μA max
• VCC regulation (VBIAS = 8 V, no load): 6.5–7 V (6.85 V typ)
• VCC UVLO rising threshold: 2.75–2.95 V (2.85 V typ)
• VCC sourcing current limit (VBIAS = 10 V, VCC = 0 V): 35 mA min, 105 mA typ
• UVLO rising threshold: 1.425–1.575 V (1.5 V typ); hysteresis current 5 μA typ
• Enable rising threshold: 0.4–0.7 V (0.52 V typ)
• Soft-start current: 9–11 μA (10 μA typ)
• Thermal resistance RθJA: 63.7 °C/W (40.8 °C/W on LM5155EVM-BST)

Features:

• Input transient protection up to 50 V
• Minimum boost supply voltage of 1.5 V when BIAS ≥ 3.5 V
• Integrated error amplifier allows primary-side regulation without an optocoupler (flyback)
• 100 mV ±7% low current limit threshold, constant peak current limiting over input voltage
• 1.5 A peak MOSFET driver; supports external VCC supply
• Dynamically programmable switching frequency, optional clock synchronization
• Optional hiccup mode short-circuit protection (LM51551 enabled, LM5155 disabled)
• Programmable line UVLO, OVP, thermal shutdown
• ±1% feedback reference (1 V)
• Programmable slope compensation, adjustable soft start, PGOOD indicator
• Functional Safety-Capable

Applications:

• Multiple-output flyback without optocoupler
• LED bias supply
• Wide input boost, SEPIC, flyback power module
• Portable speaker
• Battery-powered boost, SEPIC, flyback

Package:

• WSON-12 (DSS), 3.00 mm × 2.00 mm

• Functional Safety-Capable
• -Documentation available to aid functional safety system design
• Wide input operating range for battery applications
• -3.5-V to 45-V operating range
• -2.97-V to 16-V when BIAS = VCC
• -Minimum boost supply voltage 1.5 V when BIAS ≥ 3.5 V
• -Input transient protection up to 50 V
• Minimized battery drain
• -Low shutdown current (IQ ≤ 2.6 μA)
• -Low operating current (I Q ≤ 480 μA)
• Small solution size and low cost
• -Maximum switching frequency of 2.2 MHz
• -12-Pin WSON package (3 mm × 2 mm)
• -Integrated error amplifier allows primary-side regulation without optocoupler (flyback)
• -Minimized undershoot during cranking (startstop application)
• Higher efficiency with low-power dissipation
• -100-mV ±7% Low current limit threshold
• -Strong 1.5-A peak standard MOSFET driver
• -Supports external VCC supply
• Avoid AM band interference and crosstalk
• -Optional clock synchronization
• -Dynamically programmable switching frequency from 100 kHz to 2.2 MHz
• Integrated protection features
• -Constant peak current limiting over input voltage
• -Optional hiccup mode short-circuit protection (see the Device Comparison Table )

Typical Boost Application

Product Folder Links:

LM5155

LM51551

• -Programmable line UVLO
• -OVP protection
• -Thermal shutdown
• Accurate ±1% accuracy feedback reference
• Programmable extra slope compensation
• Adjustable soft start
• PGOOD indicator
• Create a custom design using the LM5155x with the WEBENCH ® power designer

• Multiple-output flyback without optocoupler
• LED bias supply
• Wide input boost, SEPIC, flyback power module
• Portable speaker application
• Battery-powered boost, SEPIC, flyback

Figure 7-1. 12-Pin WSON DSS Package (Top View)

Table 7-1. Pin Functions

(1) G = Ground, I = Input, O = Output, P = Power

Table 7-1. Pin Functions

Typical values correspond to TJ = 25°C. Minimum and maximum limits apply over TJ = -40°C to 125°C. Unless otherwise stated, V BIAS = 12 V, RT = 9.09 kΩ

Typical values correspond to TJ = 25°C. Minimum and maximum limits apply over TJ = -40°C to 125°C. Unless otherwise stated, V BIAS = 12 V, RT = 9.09 kΩ

Over the recommended operating junction temperature range (1)

• (2) This pin is not specified to have an external voltage applied.
• (3) 18 V or VBIAS + 0.3 V whichever is lower
• (4) The maximum current sink is limited to 1 mA when VPGOOD>VBIAS.
• (5) This pin has an internal max voltage clamp which can handle up to 1.6 mA.
• (6) High junction temperatures degrade operating lifetimes. Operating lifetime is de-rated for junction temperatures greater than 125°C.

Over the recommended operating junction temperature range of -40°C to 125°C (unless otherwise specified) (1)

See the How to Design a Boost Converter Using LM5155-Q1 application note for information on loop response and component selections for the boost converter.