LM25116MH/NOPB National Semiconductor, LM25116MH/NOPB Datasheet
LM25116MH/NOPB
Specifications of LM25116MH/NOPB
*LM25116MH/NOPB
LM25116MH
Available stocks
Related parts for LM25116MH/NOPB
LM25116MH/NOPB Summary of contents
Page 1
... The device is available in a power enhanced TSSOP-20 package featuring an exposed die attach pad to aid thermal dissipation. Typical Application © 2008 National Semiconductor Corporation Features ■ Emulated peak current mode ■ ...
Page 2
Connection Diagram Ordering Information Ordering Number Package Type LM25116MH TSSOP-20EP LM25116MHX TSSOP-20EP Pin Descriptions Pin Name Description 1 VIN Chip supply voltage, input voltage monitor and input to the VCC regulator. 2 UVLO If the UVLO pin is below 1.215V, ...
Page 3
Pin Name Description 12 CS Current sense amplifier input. Connect to the top of the current sense resistor or the drain of the low-sided MOSFET if R current sensing is used. DS(ON) 13 CSG Current sense amplifier input. Connect to ...
Page 4
... 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 VCC, VCCX, UVLO to GND (Note 3) SW GND VOUT to GND CSG to GND LO to GND SS to GND FB to GND DEMB to GND Electrical Characteristics junction temperature range of -40° ...
Page 5
Symbol Parameter Soft Start SS Current Source SS Diode Emulation Ramp Disable Threshold Offset SS Output Low Voltage Error Amplifier V FB Reference Voltage REF FB Input Bias Current COMP Sink/Source Current A DC Gain OL f ...
Page 6
Symbol Parameter HO Gate Driver V HO Low-state Output Voltage OLH V HO High-state Output Voltage OHH HO Rise Time HO High-side Fall Time I Peak HO Source Current OHH I Peak HO Sink Current OLH under-voltage ...
Page 7
Typical Performance Characteristics Typical Application Circuit Efficiency Driver Dead-time vs Temperature Driver Sink Current vs VCC Driver Source Current vs VCC 30015603 HO High R 30015605 HO Low R 30015607 7 30015604 vs VCC DS(ON) 30015606 vs VCC DS(ON) 30015608 ...
Page 8
LO High R DS(ON) LO Low R DS(ON) Forced HO Off-time vs Temperature VCCX = 5V www.national.com vs VCC 30015609 vs VCC 30015611 30015613 8 EN Input Threshold vs Temperature 30015610 UVLO vs Temperature 30015612 HB DC ...
Page 9
Frequency 30015615 Frequency vs Temperature 30015617 Frequency vs Temperature 30015619 Error Amp Gain vs Frequency Error Amp Phase vs Frequency Current Limit Threshold vs Temperature 9 30015616 30015618 30015620 www.national.com ...
Page 10
VIN Operating Current vs Temperature VCC UVLO vs Temperature VCC vs ICC www.national.com VCC vs Temperature 30015621 30015623 VCCX Switch R 30015625 10 30015622 VCC vs VIN 30015624 vs VCCX DS(ON) 30015626 ...
Page 11
Block Diagram and Typical Application Circuit 11 www.national.com ...
Page 12
Detailed Operating Description The LM25116 high voltage switching regulator features all of the functions necessary to implement an efficient high voltage buck regulator using a minimum of external components. This easy to use regulator integrates high-side and low-side MOS- FET ...
Page 13
FIGURE 5. EN Bias Current vs Voltage UVLO An under-voltage lockout pin is provided to disable the regu- lator without entering shutdown. If the UVLO pin is pulled below 1.215V, the regulator enters a standby mode of oper- ation with ...
Page 14
The sample-and-hold DC level is derived from a measure- ment of the recirculating current through either the low-side MOSFET or current sense resistor. The voltage level across the MOSFET or sense resistor is sampled and held just prior to the ...
Page 15
To further protect the external switches during prolonged current limit conditions, an internal counter counts clock pulses when in current limit. When the counter detects 256 consecutive clock cycles, the regulator enters a ...
Page 16
During this initial charging voltage, the LM25116 will force diode emulation. That is, the low-side MOSFET will turn off for the remainder of a cycle if the sensed inductor current becomes negative. The inductor current is sensed ...
Page 17
Higher ripple current allows for a smaller inductor size, but places more of a burden on the output capacitor to smooth the ripple current for low output ripple voltage. For this example, 40% ripple current was chosen for a ...
Page 18
The converter exhibits a negative input impedance which is lowest at the minimum input voltage: The damping factor for the input filter is given by: Where R is the input wiring resistance and ESR is the series IN resistance of ...
Page 19
The voltage at the UVLO pin should never exceed 16V when using an external set-point divider. It may be necessary to clamp the UVLO pin at high input voltages. For the design example 102kΩ and R = 21kΩ ...
Page 20
FIGURE 11. Modulator Gain and Phase Components R and C configure the error amplifier COMP COMP as a type II configuration. The DC gain of the amplifier is 80dB which has a pole at low frequency and a zero at ...
Page 21
The regulator has an exposed thermal pad to aid power dis- sipation. Selecting MOSFETs with exposed pads will aid the power dissipation of these devices. Careful attention high temperature should be observed. Also, at 250 kHz, (ON) ...
Page 22
MODULATOR TRANSFER FUNCTION The following equations can be used to calculate the control- to-output transfer function the effective DC gain of the modulating comparator. The m duty cycle the proportional ...
Page 23
23 www.national.com ...
Page 24
TABLE 1. Bill of Materials for 7V-42V Input Output, 250kHz ID Part Number C1, C2, C14 C2012X7R1E105K C3 VJ0603Y103KXAAT C4 VJ0603A271JXAAT C5, C15 VJ0603Y101KXAT W1BC C6 VJ0603Y332KXXAT C7 C8, C9, C10, C4532X7R2A225M C11 C12 C3225X7R2A105M C13 C2012X7R2A104M C16, ...
Page 25
Physical Dimensions inches (millimeters) unless otherwise noted TSSOP-20EP Outline Drawing NS Package Number MXA20A 25 www.national.com ...
Page 26
... For more National Semiconductor product information and proven design tools, visit the following Web sites at: 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 ...