The LM5017 is a 100-V, 600-mA synchronous stepdown regulator with integrated high side and low side MOSFETs. The constant on-time (COT) control scheme employed in the LM5017 requires no loop compensation, provides excellent transient response, and enables very high step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.
A peak current limit circuit protects against overload conditions. The undervoltage lockout (UVLO) circuit allows the input undervoltage threshold and hysteresis to be independently programmed. Other protection features include thermal shutdown and bias supply undervoltage lockout (VCC UVLO).
The LM5017 device is available in WSON-8 and HSOP PowerPAD-8 plastic packages.
PART NUMBER | PACKAGE(1) | BODY SIZE (NOM) |
---|---|---|
LM5017 | SO PowerPAD (8) | 4.89 mm × 3.90 mm |
WSON (8) | 4.00 mm × 4.00 mm |
Changes from Revision J (November 2017) to Revision K (August 2021)
Changes from Revision I (October 2015) to Revision J (November 2017)
PIN | I/O | DESCRIPTION | APPLICATION INFORMATION | |
---|---|---|---|---|
NO. | NAME | |||
1 | RTN | — | Ground | Ground connection of the integrated circuit. |
2 | VIN | P | Input voltage | Operating input range is 7.5 V to 100 V. |
3 | UVLO | I | Undervoltage comparator input | Resistor divider from VIN to UVLO to GND programs the undervoltage detection threshold. An internal current source is enabled when UVLO is above 1.225 V to provide hysteresis. When UVLO pin is pulled below 0.66 V externally, the regulator is in shutdown mode. |
4 | RON | I | On-time control | A resistor between this pin and VIN sets the buck switch on-time as a function of VIN. Minimum recommended on-time is 100 ns at maximum input voltage. |
5 | FB | I | Feedback | This pin is connected to the inverting input of the internal regulation comparator. The regulation level is 1.225 V. |
6 | VCC | O | Output from the internal high-voltage series pass regulator. Regulated at 7.6 V. | The internal VCC regulator provides bias supply for the gate drivers and other internal circuitry. A 1-μF decoupling capacitor is recommended. |
7 | BST | I | Bootstrap capacitor | An external capacitor is required between the BST and SW pins (0.01-μF ceramic). The BST capacitor is charged by the VCC regulator through an internal diode when SW is low. |
8 | SW | P | Switching node | Power switching node. Connect to the output inductor and bootstrap capacitor. |
EP | — | Exposed Pad | Exposed pad must be connected to the RTN pin. Solder to the system ground plane on application board for reduced thermal resistance. |