LM25069MM-2EVAL National Semiconductor, LM25069MM-2EVAL Datasheet
LM25069MM-2EVAL
Specifications of LM25069MM-2EVAL
Related parts for LM25069MM-2EVAL
LM25069MM-2EVAL Summary of contents
Page 1
... The LM25069-1 latches off after a fault detection, while the LM25069-2 automatically restarts at a fixed duty cycle. The LM25069 is available pin MSOP package. Typical Application © 2010 National Semiconductor Corporation LM25069 Features ■ Operating range: +2.9V to +17V ■ ...
Page 2
Connection Diagram Ordering Information Order Number Fault Response Package Type LM25069PMME-1 Latch Off LM25069PMM-1 Latch Off LM25069PMMX-1 Latch Off LM25069PMME-2 Auto Restart LM25069PMM-2 Auto Restart LM25069PMMX-2 Auto Restart Pin Descriptions Pin # Name Description 1 SENSE Current sense input 2 ...
Page 3
... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN to GND (Note 5) SENSE, OUT, PGD to GND UVLO to GND OVLO to GND VIN to SENSE ESD Rating (Note 2) Human Body Model Storage Temperature ...
Page 4
... Note 3: OUT bias current (disabled) due to leakage current through an internal 1.0 MΩ resistance from SENSE to VOUT. Note 4: For detailed information on soldering plastic MSOP packages refer to the Packaging Databook available from National Semiconductor Corporation. Note 5: Current out of a pin is indicated as a negative number. ...
Page 5
Typical Performance Characteristics 25° 12V IN VIN Pin Input Current vs. VIN OUT Pin Input Current GATE Pin Source Current Unless otherwise specified the following conditions apply: T SENSE Pin Input Current 30086703 GATE Pin Voltage 30086705 MOSFET ...
Page 6
PGD Pin Low Voltage vs. Sink Current UVLO Threshold vs. Temperature OVLO Threshold vs. Temperature www.national.com Input Current, Enabled vs. Temperature 30086708 UVLO Hysteresis Current vs. Temperature 30086757 OVLO Hysteresis Current vs. Temperature 30086766 6 30086758 30086755 30086756 ...
Page 7
Current Limit Threshold vs. Temperature Power Limit Threshold vs. Temperature GATE Source Current vs. Temperature Circuit Breaker Threshold vs. Temperature 30086759 GATE Output Voltage vs. Temperature 30086761 PGD Low Voltage vs. Temperature 30086763 7 30086760 30086762 30086765 www.national.com ...
Page 8
Block Diagram www.national.com FIGURE 1. Basic Application Circuit 8 30086710 30086711 ...
Page 9
Functional Description The LM25069 is designed to control the in-rush current to the load upon insertion of a circuit card into a live backplane or other "hot" power source, thereby limiting the voltage sag on the backplane’s supply voltage, and ...
Page 10
Gate Control A charge pump provides the voltage at the GATE pin to en- hance the N-Channel MOSFET’s gate. During normal oper- ating conditions (t3 in Figure 3) the gate held charged by an internal 20 µA ...
Page 11
Higher values may result in instability in the current limit control loop. Circuit Breaker If the load current increases rapidly (e.g., the load is short- circuited) the current in the sense resistor (R the current limit threshold before the ...
Page 12
Under-Voltage Lock-Out (UVLO) The series pass MOSFET (Q1) is enabled when the input supply voltage ( within the operating range defined by SYS the programmable under-voltage lockout (UVLO) and over- voltage lock-out (OVLO) levels. Typically the UVLO level ...
Page 13
Application Information (Refer to Figure 1) CURRENT LIMIT The LM25069 monitors the current in the external MOSFET (Q1) by measuring the voltage across the sense resistor (R ), connected from VIN to SENSE. The required resistor S value ...
Page 14
A) Turn-on with current limit only: The current limit thresh- old ( determined by the current sense resistor (R LIM the current limit threshold is less than the current defined by the power limit threshold at maximum V ...
Page 15
MOSFET SELECTION It is recommended that the external MOSFET (Q1) selection be based on the following criteria: - The BV rating should be greater than the maximum DSS system voltage (V ), plus ringing and transients which can SYS occur ...
Page 16
LM25069-2 is calculated using this shorter time period: For example, if the desired Fault Timeout Period is 17 ms, C calculates to 0.96 µF. When the Fault Timeout Period of T the LM25069-2 expires, ...
Page 17
FIGURE 12. Programming the Four Thresholds The four resistor values are calculated as follows: - Choose the upper and lower UVLO thresholds ( UVL -Choose the upper and lower OVLO threshold ( OVL FIGURE 13. UVLO ...
Page 18
increases above 1.9V. A pull-up resistor is required DS at PGD as shown in Figure 14. The pull-up voltage ( high as 17V, and can be higher or lower than the volt- ages at VIN ...
Page 19
LM25069. In the voltage at the UVLO pin goes to ground before V is removed from the LM25069 due to the shorter edge FIGURE 16. Recommended Board Connector Design Figure 16 connector pin. When the ...
Page 20
System Considerations A) Continued proper operation of the LM25069 hot swap cir- cuit requires capacitance be present on the supply side of the connector into which the hot swap circuit is plugged in, as depicted in Figure 2. The capacitor ...
Page 21
Physical Dimensions inches (millimeters) unless otherwise noted NS Package Number MUB10A 21 www.national.com ...
Page 22
... For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...