|
Details, datasheet, quote on part number:LM2618BTL
| |
| Part: | LM2618BTL |
| Category: | Power Management => Regulators => Switching Regulators |
| Description: | LM2618 - 400mA Sub-miniature, High Efficiency, Synchronous PWM & PFM Programmable DC-DC Converter, Package: Microsmd, Pin Nb=10 |
| Company: | National Semiconductor Corporation |
| Datasheet: | Download LM2618BTL datasheet File size : 439 kB |
| Request For quote: | Find where to buy LM2618BTL
|
| |
Datasheet text preview:
LM2618 400mA Sub-miniature, High Efficiency, Synchronous PWM & PFM Programmable DC-DC Converter
September 2002
LM2618 400mA Sub-miniature, High Efficiency, Synchronous PWM & PFM Programmable DC-DC Converter
General Description
The LM2618 step-down DC-DC converter is optimized for powering low voltage circuits from a single Lithium-Ion cell. It provides up to 400mA (300mA for B grade), over an input voltage range of 2.8V to 5.5V. Pin programmable output voltages of 1.80V, 1.83V, 1.87V or 1.92V allow adjustment for MPU voltage options without board redesign or external feedback resistors. Internal synchronous rectification provides high efficiency in both PWM and PFM operation. The device has three pin-selectable modes for maximizing battery life in mobile phones and similar portable applications. Low-noise PWM mode offers 600kHz fixed-frequency operation to reduce interference in RF and data acquisition applications during full-power operation. A SYNC input allows synchronizing the switching frequency in a range of 500kHz to 1MHz to avoid noise from intermodulation with system frequencies. Low-current hysteretic PFM mode reduces quiescent current to 180 µA (typ.) during system standby. Shutdown mode turns the device off and reduces battery consumption to 0.02µA (typ.). Additional features include soft start and current overload protection. The LM2618 is available in a 10 pin micro SMD packge. This package uses National's wafer level chip-scale micro SMD technology and offers the smallest possible size. Only three small external surface-mount components, an inductor and two ceramic capacitors are required.
Key Specifications
n Operates from a single LiION cell (2.8V to 5.5V) n Internal synchronous rectification provides high efficiency in both PWM and PFM n Pin programmable output voltage (1.80V, 1.83V, 1.87V and 1.92V) n 400mA maximum load capability (300mA for B grade) n ± 2% PWM mode DC output voltage precision n 5mV typ PWM mode output voltage ripple n 180 µA typ PFM mode quiescent current n 0.02µA typ shutdown mode current n Internal synchronous rectification for high efficiency (91% at 3.0VIN, 1.92VOUT) n 600kHz PWM mode switching frequency n SYNC input for PWM mode frequency synchronization from 500kHz to 1MHz
Features
n Sub-miniature 10-pin micro SMD package n Only three tiny surface-mount external components required n Uses small ceramic capacitors. n Internal soft start n Current overload protection n Thermal Shutdown Protection n No external compensation required
Applications
n Mobile Phones n Hand-Held Radios n Battery Powered Devices
Typical Application Circuit
20036402
© 2002 National Semiconductor Corporation
DS200364
www.national.com
LM2618
Connection Diagrams
micro SMD package
20036404
TOP VIEW
20036405
BOTTOM VIEW
Ordering Information
Order Number 10-Pin micro SMD LM2618ATL LM2618BTL LM2618ATLX LM2618BTLX
(*) XY - denotes the date code marking (2 digit) in production (*) TT - refers to die run/lot traceability for production (*) I - pin one indication (*) S - Product line designator Note that Package Marking may change over the course of production
Package Type
NSC Package Marking(*) XYTT IS55A
Supplied As
250 Units, Tape and Reel 250 Units, Tape and Reel 3000 Units, Tape and Reel 3000 Units, Tape and Reel
10-bump Wafer Level Chip Scale (micro SMD)
XYTT IS55B XYTT IS55A XYTT IS55B
www.national.com
2
LM2618
Pin Description
Pin Number (*) A1 B1 C1 D1 Pin Name FB VID1 VID0 SYNC/MODE Function Feedback Analog Input. Connect to the output at the output filter capacitor (Figure 1) Output Voltage Control Inputs. Set the output voltage using these digital inputs (see Table 1). The output defaults to 1.87V if these pins are unconnected. Synchronization Input. Use this digital input for frequency selection or modulation control. Set: SYNC/MODE = high for low-noise 600kHz PWM mode SYNC/MODE = low for low-current PFM mode SYNC/MODE = a 500kHz - 1MHz external clock for synchronization to an external clock in PWM mode. See Synchronization and Operating Modes in the Device Information section. Enable Input. For shutdown, set low to SGND. (See Shut down Mode in the Device Information section.) Power Ground Switching Node connection to the internal PFET switch and NFET synchronous rectifier. Connect to an inductor with a saturation current rating that exceeds the max Switch Peak Current Limit specification of the LM2618 (Figure 1) Power Supply Input to the internal PFET switch. Connect to the input filter capacitor (Figure 1). Analog Supply Input. If board layout is not optimum, an optional 0.1µF ceramic capacitor is suggested (Figure 1) Analog and Control Ground
D2 D3 C3
EN PGND SW
B3 A3 A2
PVIN VDD SGND
(*) Note that the pin numbering scheme for the microSMD package was revised in April,2002 to conform to JEDEC standard. Only the pin numbers were revised. No changes to the physical location of the inputs/outputs were made. For reference purpose, the obsolete numbering had FB as pin 1, VID1 as pin 2, VID0 as pin 3, SYNC as pin 4, EN as pin 5, PGND as pin 6, SW as pin 7, PVIN as pin 8, VDD as pin 9 and SGND as pin 10.
3
www.national.com
|
|
