LT1612ES8 Linear Technology, LT1612ES8 Datasheet - Page 7

• Manufacturer Part Number: LT1612ES8
• Description: IC CONV DC/DC PWM STEPDOWN 8SOIC
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LT1612ES8

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: Adj to 0.6V
• Current - Output: 500mA
• Frequency - Switching: 800kHz
• Voltage - Input: 2 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

OPERATIO
Burst Mode Operation Defeat
To maintain high efficiency at light loads, the LT1612 will
automatically shift into Burst Mode operation (MODE = 0V
or floating). In this mode of operation the oscillator and
switch drive circuitry is alternately turned on and off,
reducing quiescent current to 160 A. This reduces power
AC COUPLED
200mA/DIV
20mV/DIV
V
OUT
Figure 3. Output Voltage Ripple is 20mV
the Circuit of Figure 1
IL
U
5 s/DIV
10mA TO 300mA
Figure 5. With the MODE Pin Tied High, Low
Frequency Output Voltage Ripple Is No Longer Present
AC COUPLED
200mV/DIV
200mA/DIV
I
V
LOAD
OUT
I
L
P-P
for
1612 F03
consumption but also adds low frequency voltage ripple to
the output. Figure 3 shows switching waveforms for a 5V
to 3.3V converter running in Burst Mode operation. Output
voltage ripple is approximately 20mV
is pulled high, Burst Mode operation will be inhibited and
the oscillator runs continuously with no low frequency
ripple at the output. See Figures 4 and 5.
0.1ms/DIV
10mA TO 310mA
Figure 4. Transient Response for the Circuit of Figure 1
with the MODE Pin Tied to Ground or Floating
AC COUPLED
200mA/DIV
200mV/DIV
I
V
LOAD
OUT
I
L
1612 F05
0.1ms/DIV
P-P
. If the MODE pin
LT1612
sn1612 1612fs
1612 F04
7