Datasheet LTC3548-1 (Analog Devices) - 5

LTC3548-1
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise specifi ed. Effi ciency vs Load Current Effi ciency vs Load Current
100 100 95 95 V V V V IN = 3.6V IN = 2.7V IN = 3.6V IN = 2.7V 90 90 85 85 VIN = 4.2V 80 80 VIN = 4.2V 75 75 EFFICIENCY (%) EFFICIENCY (%) 70 70 V V 65 OUT1 = 1.8V 65 OUT2 = 1.575V NO LOAD ON OTHER CHANNEL NO LOAD ON OTHER CHANNEL CIRCUIT OF FIGURE 3 CIRCUIT OF FIGURE 3 60 60 1 10 100 1000 1 10 100 1000 LOAD CURRENT (mA) LOAD CURRENT (mA) 3548-1 G16 3548-1 G17
PIN FUNCTIONS VFB1 (Pin 1):
Output Feedback for Channel 1. Receives the to shut down. This pin must be driven; do not fl oat. feedback voltage from internal resistive divider across the
SW2 (Pin 7):
Regulator 2 Switch Node Connection to the output. Normal voltage for this pin is 0.6V. Inductor. This pin swings from VIN to GND.
VOUT1 (Pin 2):
Output Voltage Feedback Pin for Channel 1.
RUN1 (Pin 8):
Regulator 1 Enable. Forcing this pin to V An internal resistive divider divides the output voltage down IN en- ables regulator 1, while forcing it to GND causes regulator 1 for comparison to the internal reference voltage. to shut down. This pin must be driven; do not fl oat.
VIN (Pin 3):
Input Power Supply. Must be closely decoupled
V
to GND.
OUT2 (Pin 9):
Output Voltage Feedback Pin for Channel 2. An internal resistive divider divides the output voltage down
SW1 (Pin 4):
Regulator 1 Switch Node Connection to the for comparison to the internal reference voltage. Inductor. This pin swings from VIN to GND.
VFB2 (Pin 10):
Output Feedback for Channel 2. Receives
GND (Pin 5):
Ground. This pin is not connected inter- the feedback voltage from internal resistive divider across nally. Connect to PCB ground for optimum shielding (see the output. Normal voltage for this pin is 0.6V. Figure 4).
Exposed Pad (GND) (Pin 11):
Ground. Connect to the
RUN2 (Pin 6):
Regulator 2 Enable. Forcing this pin to VIN en- (–) terminal of COUT, and (–) terminal of CIN. Must be con- ables regulator 2, while forcing it to GND causes regulator 2 nected to electrical ground on PCB (see Figure 4). 35481fc 5