Datasheet LT3681 (Analog Devices) - 7
| 制造商 | Analog Devices |
| 描述 | 36V, 2A, 2.8MHz Step-Down Switching Regulator with Integrated Power Schottky Diode |
| 页数 / 页 | 24 / 7 — PI FU CTIO S. PG (Pin 1):. BD (Pin 10):. BOOST (Pin 11):. BIAS (Pin 2):. … |
| 文件格式/大小 | PDF / 381 Kb |
| 文件语言 | 英语 |
PI FU CTIO S. PG (Pin 1):. BD (Pin 10):. BOOST (Pin 11):. BIAS (Pin 2):. SW (Pin 12):. FB (Pin 3):. IN (Pin 13):. VC (Pin 5):
该数据表的模型线
文件文字版本
LT3681
U U U PI FU CTIO S PG (Pin 1):
The PG pin is the open collector output of an
BD (Pin 10):
This pin connects to the anode of the internal internal comparator. PG remains low until the FB pin is boost Schottky diode. within 10% of the fi nal regulation voltage. PG output is
BOOST (Pin 11):
This pin is used to provide a drive valid when VIN is above 3.5V and RUN/SS is high. voltage, higher than the input voltage, to the internal
BIAS (Pin 2):
The BIAS pin supplies the current to the bipolar NPN power switch. Connect a capacitor between LT3681’s internal regulator. Tie this pin to the lowest this pin and SW. available voltage source above 3V (typically VOUT). This
SW (Pin 12):
The SW pin is the output of the internal architecture increases effi ciency especially when the input power switch. Connect this pin to the inductor, DC and voltage is much higher than the output. boost capacitor.
FB (Pin 3):
The LT3681 regulates the FB pin to 1.265V.
V
Connect the feedback resistor divider tap to this pin.
IN (Pin 13):
The VIN pin supplies current to the LT3681’s internal regulator and to the internal power switch. This
VC (Pin 5):
The VC pin is the output of the internal error pin must be locally bypassed. amplifi er. The voltage on this pin controls the peak switch
RUN/SS (Pin 14):
The RUN/SS pin is used to put the current. Tie an RC network from this pin to ground to LT3681 in shutdown mode. Tie to ground to shut down compensate the control loop. the LT3681. Tie to 2.3V or more for normal operation. If
RT (Pin 6):
Oscillator Resistor Input. Connecting a resistor the shutdown feature is not used, tie this pin to the VIN to ground from this pin sets the switching frequency. pin. RUN/SS also provides a soft-start function; see the Applications Information section.
DA (Pin 8):
This is the anode of the integrated power Schottky diode. High frequency, large amplitude currents
GND (Pins 4, 7, Exposed Pad 15):
All three of these fl ow through this pin, so tie it to ground through a low terminals internally connect to the LT3681 control IC’s impedance connection. signal return, while exposed pad 15 performs the added function of providing a low thermal resistance heat fl ow
DC (Pin 9, Exposed Pad 16):
These pins connect to the path between the IC and the system heatsink. Tie all of cathode of the integrated power Schottky diode. High fre- these terminals to a copper pour on the top layer of the quency, large amplitude currents fl ow through these pins, printed circuit board. Please refer to the Applications so tie them to SW through a low impedance connection. Information section for more details. 3681f 7
U U U PI FU CTIO S PG (Pin 1):
The PG pin is the open collector output of an
BD (Pin 10):
This pin connects to the anode of the internal internal comparator. PG remains low until the FB pin is boost Schottky diode. within 10% of the fi nal regulation voltage. PG output is
BOOST (Pin 11):
This pin is used to provide a drive valid when VIN is above 3.5V and RUN/SS is high. voltage, higher than the input voltage, to the internal
BIAS (Pin 2):
The BIAS pin supplies the current to the bipolar NPN power switch. Connect a capacitor between LT3681’s internal regulator. Tie this pin to the lowest this pin and SW. available voltage source above 3V (typically VOUT). This
SW (Pin 12):
The SW pin is the output of the internal architecture increases effi ciency especially when the input power switch. Connect this pin to the inductor, DC and voltage is much higher than the output. boost capacitor.
FB (Pin 3):
The LT3681 regulates the FB pin to 1.265V.
V
Connect the feedback resistor divider tap to this pin.
IN (Pin 13):
The VIN pin supplies current to the LT3681’s internal regulator and to the internal power switch. This
VC (Pin 5):
The VC pin is the output of the internal error pin must be locally bypassed. amplifi er. The voltage on this pin controls the peak switch
RUN/SS (Pin 14):
The RUN/SS pin is used to put the current. Tie an RC network from this pin to ground to LT3681 in shutdown mode. Tie to ground to shut down compensate the control loop. the LT3681. Tie to 2.3V or more for normal operation. If
RT (Pin 6):
Oscillator Resistor Input. Connecting a resistor the shutdown feature is not used, tie this pin to the VIN to ground from this pin sets the switching frequency. pin. RUN/SS also provides a soft-start function; see the Applications Information section.
DA (Pin 8):
This is the anode of the integrated power Schottky diode. High frequency, large amplitude currents
GND (Pins 4, 7, Exposed Pad 15):
All three of these fl ow through this pin, so tie it to ground through a low terminals internally connect to the LT3681 control IC’s impedance connection. signal return, while exposed pad 15 performs the added function of providing a low thermal resistance heat fl ow
DC (Pin 9, Exposed Pad 16):
These pins connect to the path between the IC and the system heatsink. Tie all of cathode of the integrated power Schottky diode. High fre- these terminals to a copper pour on the top layer of the quency, large amplitude currents fl ow through these pins, printed circuit board. Please refer to the Applications so tie them to SW through a low impedance connection. Information section for more details. 3681f 7