lm20133mhx National Semiconductor Corporation, lm20133mhx Datasheet
lm20133mhx
Available stocks
Related parts for lm20133mhx
lm20133mhx Summary of contents
Page 1
... The LM20133 is offered in a 16-pin eTSSOP package with an exposed pad that can be soldered to the PCB, eliminating the need for bulky heatsinks. Typical Application Circuit ® PowerWise is a registered trademark of National Semiconductor Corporation. © 2007 National Semiconductor Corporation Synchronous Buck Regulator with Input Features ■ Input voltage range 2.95V to 5.5V ■ ...
Page 2
... Connection Diagram Ordering Information Order Number Package Type LM20133MH eTSSOP-16 LM20133MHE LM20133MHX Pin Descriptions Pin # Name 1 SS/TRK Soft-Start or Tracking control input. An internal 5 µA current source charges an external capacitor to set the Soft-Start ramp rate. If driven by a external source less than 800 mV, this pin overrides the internal reference that sets the output voltage ...
Page 3
Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Voltages from the indicated pins to GND AVIN, PVIN, EN, PGOOD, SS/ TRK, COMP, FB, SW, SYNC Storage Temperature ...
Page 4
Symbol Parameter Enable V EN Pin Turn on Threshold IH_EN V EN Pin Hysteresis EN_HYS Thermal Shutdown T Thermal Shutdown SD T Thermal Shutdown Hysteresis SD_HYS Thermal Resistance θ Junction to Ambient JA Note 1: Absolute Maximum Ratings indicate limits ...
Page 5
Efficiency vs. Load Current ( High-Side FET resistance vs. Temperature Error Amplifier Gain vs. Frequency = 500 kHz) Efficiency vs. Load Current (V SW 30030349 Low-Side FET resistance vs. Temperature 30030352 30030336 5 = 3.3V, f ...
Page 6
Load Regulation Switching Frequency vs. Temperature Quiescent Current vs. V www.national.com 30030338 30030339 (Not Switching) IN 30030340 6 Feedback Voltage vs. Temperature 30030351 Switch Synchronization 30030360 Shutdown Current vs. Temperature 30030341 ...
Page 7
Enable Threshold vs. Temperature 30030328 Peak Current Limit vs. Temperature 30030342 Peak Current Limit vs 30030356 UVLO Threshold vs. Temperature Peak Current Limit vs. V Load Transient Response 7 30030345 OUT 30030354 30030334 www.national.com ...
Page 8
Line Transient Response Start-Up (Tracking) Short Circuit Input Current vs. V www.national.com 30030343 30030333 IN 30030355 8 Start-Up (Soft-Start) 30030344 Power Down 30030332 P vs. I GOOD PGOOD 30030327 ...
Page 9
Block Diagram 9 30030303 www.national.com ...
Page 10
Operation Description GENERAL The LM20133 switching regulator features all of the functions necessary to implement an efficient low voltage buck regula- tor using a minimum number of external components. This easy to use regulator features two integrated switches and is ...
Page 11
Typical values for the PGOOD resistor are on the or- der of 100 kΩ or less. To avoid false tripping during transient glitches the PGOOD pin has 16 µs of built in deglitch time to both rising and ...
Page 12
FIGURE 1. Modes of Operation for LM20133 12 30030305 ...
Page 13
Design Guide This section walks the designer through the steps necessary to select the external components to build a fully functional power supply. As with any DC-DC converter numerous trade- offs are possible to optimize the design for efficiency, size, ...
Page 14
Where, C (F) is the minimum required output capacitance, OUT L (H) is the value of the inductor, V voltage drop ignoring loop bandwidth considerations, ΔI (A) is the load step change, R STEP capacitor ESR, V (V) is the ...
Page 15
The power stage transfer function is dictated by the modula- tor, output LC filter, and load; while the feedback transfer function is set by the feedback resistor ratio, error amp gain, and external compensation network. To achieve a -20dB/decade slope, ...
Page 16
FIGURE 6. Sequencing LM20133 with Precision Enable The value for resistor R can be selected by the user to control B the current through the divider. Typically this resistor will be selected to be between 10 kΩ and 1 MΩ. ...
Page 17
T is the ambient temperature in ° the output load current. OUT DCR is the inductor series resistance important to always keep the operating junction temper- ature (T ) below 125°C for reliable operation. If ...
Page 18
FIGURE 10. Schematic of LM20133 Highlighting Layout Sensitive Nodes www.national.com 30030322 18 ...
Page 19
Typical Application Circuits This section provides several application solutions with a bill of materials. All bill of materials reference the below figure. Bill of Materials ( Designator Description U1 Synchronous Buck Regulator C 47 µF, 1210, ...
Page 20
Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 16-Lead eTSSOP Package NS Package Number MXA16A 20 ...
Page 21
Notes 21 www.national.com ...
Page 22
... National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. ...