LM5575MHX/NOPB National Semiconductor, LM5575MHX/NOPB Datasheet

IC BUCK SYNC ADJ 1.5A 16TSSOP

LM5575MHX/NOPB

Manufacturer Part Number
LM5575MHX/NOPB
Description
IC BUCK SYNC ADJ 1.5A 16TSSOP
Manufacturer
National Semiconductor
Series
PowerWise®, SIMPLE SWITCHER®r
Type
Step-Down (Buck)r
Datasheet

Specifications of LM5575MHX/NOPB

Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.23 ~ 70 V
Current - Output
1.5A
Frequency - Switching
200kHz, 485kHz
Voltage - Input
6 ~ 75 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
Power - Output
2.1W
For Use With
LM5575BLDT - WEBENCH BUILD IT BOARD LM5575LM5575EVAL - BOARD EVALUATION FOR LM5575
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
LM5575MHX

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM5575MHX/NOPB
Manufacturer:
TI/德州仪器
Quantity:
20 000
Part Number:
LM5575MHX/NOPB
Manufacturer:
TI
Quantity:
8 482
Part Number:
LM5575MHX/NOPB
0
© 2009 National Semiconductor Corporation
SIMPLE SWITCHER® 75V, 1.5A Step-Down Switching
Regulator
General Description
The LM5575 is an easy to use SIMPLE SWITCHER® buck
regulator which allows design engineers to design and opti-
mize a robust power supply using a minimum set of compo-
nents. Operating with an input voltage range of 6 - 75V, the
LM5575 delivers 1.5A of continuous output current with an
integrated 330mΩ N-Channel MOSFET. The regulator uti-
lizes an Emulated Current Mode architecture which provides
inherent line regulation, tight load transient response, and
ease of loop compensation without the usual limitation of low-
duty cycles associated with current mode regulators. The
operating frequency is adjustable from 50kHz to 500kHz to
allow optimization of size and efficiency. To reduce EMI, a
frequency synchronization pin allows multiple IC’s from the
LM(2)557x family to self-synchronize or to synchronize to an
external clock. The LM5575 guarantees robustness with cy-
cle-by-cycle current limit, short-circuit protection, thermal
shut-down, and remote shut-down. The device is available in
a power enhanced TSSOP-16 package featuring an exposed
die attach pad for thermal dissipation. The LM5575 is sup-
ported by the full suite of WEBENCH
Simplified Application Schematic
WEBENCH
®
is a registered trademark of National Semiconductor Corporation.
®
On-Line design tools.
202088
LM5575/LM5575Q
Features
Package
Applications
LM5575Q is an Automotive Grade product that is AEC-
Q100 grade 1 qualified (−40°C to + 125°C operating
junction temperature)
Integrated 75V, 330mΩ N-channel MOSFET
Ultra-wide input voltage range from 6V to 75V
Adjustable output voltage as low as 1.225V
1.5% feedback reference accuracy
Operating frequency adjustable between 50kHz and
500kHz with single resistor
Master or slave frequency synchronization
Adjustable soft-start
Emulated current mode control architecture
Wide bandwidth error amplifier
Built-in protection
Automotive Grade product datasheet that is AEC-Q100
grade 0 qualified is available upon request.
(−40°C to + 150°C operating junction temperature)
TSSOP-16EP (Exposed Pad)
Automotive
Industrial
20208801
March 23, 2009
www.national.com

Related parts for LM5575MHX/NOPB

LM5575MHX/NOPB Summary of contents

Page 1

... TSSOP-16 package featuring an exposed die attach pad for thermal dissipation. The LM5575 is sup- ported by the full suite of WEBENCH Simplified Application Schematic WEBENCH ® registered trademark of National Semiconductor Corporation. © 2009 National Semiconductor Corporation LM5575/LM5575Q Features ■ LM5575Q is an Automotive Grade product that is AEC- Q100 grade 1 qualified (− ...

Page 2

Connection Diagram Ordering Information Order Number Package Type LM5575MH Exposed Pad TSSOP-16 MXA16A LM5575MHX Exposed Pad TSSOP-16 MXA16A LM5575QMH Exposed Pad TSSOP-16 MXA16A LM5575QMHX Exposed Pad TSSOP-16 MXA16A * Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for ...

Page 3

Pin Descriptions Pin(s) Name 1 VCC Output of the bias regulator 2 SD Shutdown or UVLO input 3 Vin Input supply voltage 4 SYNC Oscillator synchronization input or output The internal oscillator can be synchronized to an external 5 COMP ...

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Pin(s) Name 16 BST Boost input for bootstrap capacitor NA EP Exposed Pad www.national.com Description An external capacitor is required between the BST and the SW pins. A 0.022µF ceramic capacitor is recommended. The capacitor is charged from Vcc via ...

Page 5

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications GND IN BST to GND PRE to GND SW to GND (Steady State) BST SD GND CC Electrical Characteristics apply over full Operating Junction Temperature range. V Symbol ...

Page 6

Symbol Parameter RAMP GENERATOR Ramp Current 1 Ramp Current 2 PWM COMPARATOR Forced Off-time Min On-time COMP to PWM Comparator Offset ERROR AMPLIFIER Feedback Voltage FB Bias Current DC Gain COMP Sink / Source Current Unity Gain Bandwidth DIODE SENSE ...

Page 7

Soft Start Current vs Temperature 20208822 7kΩ L 20208824 Demoboard Efficiency vs I and V OUT IN 20208826 12V IN Error Amplifier Gain/Phase A = 101 ...

Page 8

Typical Application Circuit and Block Diagram www.national.com 8 ...

Page 9

Detailed Operating Description The LM5575 switching regulator features all of the functions necessary to implement an efficient high voltage buck regu- lator using a minimum of external components. This easy to use regulator integrates a 75V N-Channel buck switch with ...

Page 10

Shutdown / Standby The LM5575 contains a dual level Shutdown (SD) circuit. When the SD pin voltage is below 0.7V, the regulator low current shutdown mode. When the SD pin voltage is greater than 0.7V but less ...

Page 11

FIGURE 5. Simplified Oscillator Block Diagram and SYNC I/O Circuit Error Amplifier and PWM Comparator The internal high gain error amplifier generates an error signal proportional to the difference between the regulated output voltage and an internal precision reference (1.225V). ...

Page 12

The sample & hold DC level illustrated in Figure 6 is derived from a measurement of the re-circulating Schottky diode an- ode current. The re-circulating diode anode should be con- nected to the IS pin. The diode current flows through ...

Page 13

Maximum Duty Cycle / Input Drop- out Voltage There is a forced off-time of 500ns implemented each cycle to guarantee sufficient time for the diode current to be sam- pled. This forced off-time limits the maximum duty cycle of the ...

Page 14

Application Information EXTERNAL COMPONENTS The procedure for calculating the external components is il- lustrated with the following design example. The Bill of Mate- rials for this design is listed in Table 1. The circuit shown in Figure 1 is configured ...

Page 15

RMS current rating and minimum ripple voltage. A good approximation for the re- quired ripple current rating necessary is I Quality ceramic capacitors with a low ESR should be selected for the input filter. To ...

Page 16

R4C5). The error amplifier zero cancels the modulator pole leaving a single pole response at the crossover frequen the loop gain. A single pole response at the crossover frequency yields a very stable loop with 90 ...

Page 17

FIGURE 12. VCC Bias from VOUT for 8V < VOUT < 14V FIGURE 13. VCC Bias with Additional Winding on the Output Inductor 17 20208818 20208819 www.national.com ...

Page 18

PCB LAYOUT AND THERMAL CONSIDERATIONS The circuit in Figure 1 serves as both a block diagram of the LM5575 and a typical application board schematic for the LM5575 buck regulator there are two loops where cur- rents are ...

Page 19

... CAPACITOR, CER, KEMET NOT USED DIODE, 100V, CENTRAL INDUCTOR, COOPER NOT USED NOT USED RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR REGULATOR, NATIONAL SEMICONDUCTOR 19 VALUE 1µ, 100V 1µ, 100V 470p, 100V 0.01µ, 100V 0.01µ, 100V 0.022µ, 100V 0.47µ, 16V 10µ, 16V 120µ ...

Page 20

PCB Layout www.national.com Component Side Solder Side Silkscreen 20 20208829 20208830 20208831 ...

Page 21

Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead TSSOP Package NS Package Number MXA16A 21 www.national.com ...

Page 22

... 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 ...

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