LM51581-Q1
The LM51581-Q1 is an electronic component from Texas Instruments. View the full LM51581-Q1 datasheet below including electrical characteristics, absolute maximum ratings.
Manufacturer
Texas Instruments
Category
Voltage Regulators - Switching
Pin Configuration
图 7-1. RTE Package 16-Pin WQFN Top View
表 7-1. Pin Functions
| PIN | PIN | TYPE (1) | DESCRIPTION |
|---|---|---|---|
| NO. | NAME | TYPE (1) | DESCRIPTION |
| 1, 16 | PGND | P | Power ground pin. Source connection of the internal N-channel power MOSFET |
| 2 | VCC | P | Output of the internal VCC regulator and supply voltage input of the internal MOSFET driver. Connect a 1-μF ceramic bypass capacitor from this pin to PGND. |
| 3 | BIAS | P | Supply voltage input to the VCC regulator. Connect a bypass capacitor from this pin to PGND. |
| 4 | PGOOD | O | Power-good indicator. An open-drain output, which goes low if FB is below the undervoltage threshold (V UVTH ). Connect a pullup resistor to the system voltage rail. |
| 5 | RT | I | Switching frequency setting pin. The switching frequency is programmed by a single resistor between RT and AGND. |
| 6 | EN/UVLO/ SYNC | I | Enable pin. The converter shuts down when the pin is less than the enable threshold (V EN ). |
| 6 | EN/UVLO/ SYNC | I | Undervoltage lockout programming pin. The converter start-up and shutdown levels can be programmed by connecting this pin to the supply voltage through a voltage divider. If using a programmable UVLO, connect the low-side UVLO resistor to AGND. This pin must not be left floating. Connect to the BIAS pin if not used. |
| 6 | EN/UVLO/ SYNC | I | External synchronization clock input pin. The internal clock can be synchronized to an external clock by applying a negative pulse signal into the pin. |
| 7 | AGND | G | Analog ground pin. Connect to the analog ground plane through a wide and short path. |
| 8 | COMP | O | Output of the internal transconductance error amplifier. Connect the loop compensation components between this pin and AGND. |
| 9 | FB | I | Inverting input of the error amplifier. Connect a voltage divider to set the output voltage in boost, SEPIC, or primary-side regulated flyback topologies. Connect the low-side feedback resistor as close to AGND as possible. |
| 10 | SS | I | Soft-start time programming pin. An external capacitor and an internal current source set the ramp rate of the internal error amplifier reference during soft start. Connect the ground connection of the capacitor to AGND. |
| 11 | MODE | I | MODE = 0 V or connect to AGND during initial power up: Hiccup mode protection is disabled and spread spectrum is disabled. |
| 11 | MODE | I | MODE = 370 mV or connect a 37.4-kΩ resistor between this pin and AGND during initial power up: Hiccup mode protection is enabled and spread spectrum is enabled. |
| 11 | MODE | I | MODE = 620 mV or connect a 62.0-kΩ resistor between this pin and AGND during initial power up: Hiccup mode protection is enabled and spread spectrum is disabled. |
| 11 | MODE | I | MODE > 1 V or connect a 100-kΩ resistor between this pin and AGND during initial power up: Hiccup mode protection is disabled and spread spectrum is enabled. |
表 7-1. Pin Functions
| PIN | PIN | TYPE (1) | DESCRIPTION |
|---|---|---|---|
| NO. | NAME | ||
| 13, 14 | SW | Switch pin. Drain connection of the internal N-channel power MOSFET | |
| 12, 15 | NC | - | No internal electrical contact |
| - | EP | - | Exposed pad of the package. The exposed pad must be connected to AGND and the large ground copper plane to decrease thermal resistance. |
Electrical Characteristics
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
| PARAMETER | PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT |
|---|---|---|---|---|---|---|
| SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT |
| I SHUTDOWN(BIAS) | BIAS shutdown current | V BIAS = 12 V, V UVLO = 0 V | 2.6 | 5 | μA | |
| I OPERATING(BIAS) | BIAS operating current | V BIAS = 12 V, V UVLO = 2.0 V, V FB = V REF , R T = 220 kΩ | 670 | 850 | μA | |
| VCC REGULATOR | VCC REGULATOR | VCC REGULATOR | VCC REGULATOR | VCC REGULATOR | VCC REGULATOR | VCC REGULATOR |
| V VCC-REG | VCC regulation | V BIAS = 8 V, I VCC = 18 mA | 4.66 | 4.9 | 5.14 | V |
| V VCC- UVLO(RISING) | VCC UVLO threshold | VCC rising | 3.05 | 3.10 | 3.15 | V |
| VCC UVLO hysteresis | VCC falling | 0.1 | V | |||
| ENABLE | ENABLE | ENABLE | ENABLE | ENABLE | ENABLE | ENABLE |
| V EN(RISING) | Enable threshold | EN rising | 0.4 | 0.52 | 0.7 | V |
| V EN(FALLING) | Enable threshold | EN falling | 0.33 | 0.49 | 0.63 | V |
| V EN(HYS) | Enable hysteresis | EN falling | 0.03 | V | ||
| UVLO/SYNC | UVLO/SYNC | UVLO/SYNC | UVLO/SYNC | UVLO/SYNC | UVLO/SYNC | UVLO/SYNC |
| V UVLO(RISING) | UVLO / SYNC threshold | UVLO rising | 1.425 | 1.5 | 1.575 | V |
| V UVLO(FALLING) | UVLO / SYNC threshold | UVLO falling | 1.370 | 1.45 | 1.520 | V |
| V UVLO(HYS) | UVLO / SYNC threshold hysteresis | UVLO falling | 0.05 | V | ||
| I UVLO | UVLO hysteresis current | V UVLO = 1.6 V | 4 | 5 | 6 | μA |
| MODE, SPREAD SPECTRUM | MODE, SPREAD SPECTRUM F SW modulation (upper limit) F SW modulation (lower limit) | MODE, SPREAD SPECTRUM | MODE, SPREAD SPECTRUM 7.8% -7.8% | MODE, SPREAD SPECTRUM | MODE, SPREAD SPECTRUM | MODE, SPREAD SPECTRUM |
| SOFT START | SOFT START | SOFT START | SOFT START | SOFT START | SOFT START | SOFT START |
| I SS | Soft-start current SS pulldown switch R DSON | 9 | 10 50 | 11 | μA Ω | |
| PULSE WIDTH MODULATION | PULSE WIDTH MODULATION | PULSE WIDTH MODULATION | PULSE WIDTH MODULATION | PULSE WIDTH MODULATION | PULSE WIDTH MODULATION | PULSE WIDTH MODULATION |
| fsw1 | Switching frequency | R T = 220 kΩ | 85 | 100 | 115 | kHz |
Absolute Maximum Ratings
Over the recommended operating junction temperature range (1)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| Input | BIAS to AGND | -0.3 | 65 | V |
| Input | UVLO to AGND | -0.3 | V BIAS + 0.3 | V |
| Input | SS, RT to AGND (2) | -0.3 | 3.8 | V |
| Input | FB to AGND | -0.3 | 4.0 | V |
| Input | MODE to AGND | -0.3 | 3.8 | V |
| Input | PGND to AGND | -0.3 | 0.3 | V |
| VCC to AGND | -0.3 | 5.8 (3) | V | |
| PGOOD to AGND (4) | -0.3 | 18 | V | |
| COMP to AGND (5) | -0.3 | V | ||
| SW to AGND (DC) | -0.3 | 85 | V | |
| SW to AGND (5-ns transient) | -6 | V | ||
| Junction temperature, T J (6) | Junction temperature, T J (6) | -40 | 150 | °C |
| Storage temperature, T stg | Storage temperature, T stg | -55 | 150 | °C |
- (1) Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions . If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings , the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
- (2) These pins are not specified to have an external voltage applied.
- (3) Operating lifetime is de-rated when the pin voltage is greater than 5.5 V.
- (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.
Recommended Operating Conditions
Over the recommended operating junction temperature range (1)
| MIN | NOM | MAX | UNIT | ||
|---|---|---|---|---|---|
| V SUPPLY | Boost converter input (when BIAS ≥ 3.2 V) | 1.5 | 60 | V | |
| V LOAD | Boost converter output | V SUPPLY | 83 (2) | V | |
| V BIAS | BIAS input (3) | 3.2 | 60 | V | |
| V UVLO | UVLO input | 0 | 60 | V | |
| V FB | FB input | 0 | 4.0 | V | |
| I SW | Switch current | 0 | See note (4) | A | |
| f SW | Typical switching frequency | 100 | 2200 | kHz | |
| f SYNC | Synchronization pulse frequency | 100 | 2200 | kHz | |
| T J | Operating junction temperature | -40 | 125 | °C |
- (2) The boost converter output can be up to 83 V, but the SW pin voltage should be less than or equal to 85 V during transient.
- (3) The BIAS pin operating range is from 3.2 V to 60 V when VCC is supplied from the internal VCC regulator.
- (4) The maximum switch current is limited by pre-programmed peak current limit (ILIM) when TJ < TTSD.
Thermal Information
| THERMAL METRIC (1) | LM5158x RTE(QFN) | UNIT | |
|---|---|---|---|
| 16 PINS | |||
| R θJA | Junction-to-ambient thermal resistance (LM5158EVM-BST) | 32.7 | °C/W |
| R θJA | Junction-to-ambient thermal resistance | 45.6 | °C/W |
| R θJC(top) | Junction-to-case (top) thermal resistance | 44.8 | °C/W |
| R θJB | Junction-to-board thermal resistance | 19.1 | °C/W |
| Ψ JT | Junction-to-top characterization parameter (LM5158EVM-BST) | 0.6 | °C/W |
| Ψ JT | Junction-to-top characterization parameter | 0.8 | °C/W |
| Ψ JB | Junction-to-board characterization parameter (LM5158EVM-BST) | 15.1 | °C/W |
| Ψ JB | Junction-to-board characterization parameter | 19.1 | °C/W |
| R θJC(bot) | Junction-to-case (bottom) thermal resistance | 6.7 | °C/W |
Typical Application
TI provides application notes explaining how to design boost and flyback converters using the device. These comprehensive application notes include component selections and loop response optimization.
See these application reports for more information on loop response and component selection:
Related Variants
The following components are covered by the same datasheet.
| Part Number | Manufacturer | Package |
|---|---|---|
| LM51581 | Texas Instruments | — |
| LM51581RTER | Texas Instruments | — |
| LM51581RTER.A | Texas Instruments | — |
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