LT3060ITS8#TRMPBF Linear Technology, LT3060ITS8#TRMPBF Datasheet - Page 17

• Manufacturer Part Number: LT3060ITS8#TRMPBF
• Description: IC REG LDO ADJ .1A 8TSOT
• Manufacturer: Linear Technology

Specifications of LT3060ITS8#TRMPBF

• Regulator Topology: Positive Adjustable
• Voltage - Output: 0.6 ~ 44.5 V
• Voltage - Input: 1.6 ~ 45 V
• Voltage - Dropout (typical): 0.3V @ 100mA
• Number Of Regulators: 1
• Current - Output: 100mA
• Current - Limit (min): 110mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-8, TSOT-8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

applicaTions inForMaTion
Table 1 shows 1% resistor divider values for some com-
mon output voltages with a resistor divider current of
about 5µA.
Table 1. Output Voltage Resistor Divider Values
Bypass Capacitance, Output Voltage Noise and
Transient Response
The LT3060 regulators provide low output voltage noise
over the 10Hz to 100kHz bandwidth while operating at
full load with the addition of a reference bypass capacitor
(C
low leakage capacitor is recommended. This capacitor
bypasses the internal reference of the regulator, provid-
ing a low frequency noise pole. With the use of 10nF for
C
30µV
output voltages (generated by using a feedback resistor
divider), the output voltage noise gains up accordingly
when using C
REF/BYP,
Figure 2. Feedforward Capacitor for Fast Transient Response
REF/BYP
RMS
V
(V)
1.2
1.5
1.8
2.5
3.3
OUT
3
5
) from the REF/BYP pin to GND. A good quality,
when the output voltage is set for 0.6V. For higher
the output voltage noise decreases to as low as
V
IN
REF/BYP
IN
SHDN
GND REF/BYP
LT3060
by itself.
OUT
ADJ
C
(k Ω)
118
121
124
115
124
124
115
REF/BYP
R1
3060 F02
R2
R1
I
C
C
FB DIVIDER
FF
FF
−
≥
4 7
5
.
µA
nF
=
C
•
R
V
OUT
(k Ω)
(
V
118
182
249
365
499
562
845
OUT
I
1 1
R2
FB DIVIDER
OUT
+R
−
2
)
To lower the output voltage noise for higher output volt-
ages, include a feedforward capacitor (C
to the ADJ pin. A good quality, low leakage capacitor is
recommended. This capacitor bypasses the error amplifier
of the regulator, providing a low frequency noise pole. With
the use of 10nF for both C
noise decreases to 30µV
set to 5V by a 5µA feedback resistor divider. If the current
in the feedback resistor divider is doubled, C
be doubled to achieve equivalent noise performance.
Higher values of output voltage noise are often measured
if care is not exercised with regard to circuit layout and
testing. Crosstalk from nearby traces induces unwanted
noise onto the LT3060’s output. Power supply ripple rejec-
tion must also be considered. The LT3060 regulators do
not have unlimited power supply rejection and will pass a
small portion of the input noise through to the output.
Using a feedforward capacitor (C
pin has the added benefit of improving transient response
for output voltages greater than 0.6V. With no feedforward
capacitor, the settling time will increase as the output
voltage is raised above 0.6V. Use the equation in Figure 2
to determine the minimum value of C
transient response that is similar to 0.6V output voltage
performance regardless of the chosen output voltage
(see Figure 3 and Transient Response in the Typical Perf-
ormance Characteristics section).
LOAD CURRENT
Figure 3. Transient Response vs Feedforward Capacitor
100mA/DIV
100pF
10nF
1nF
0
100µs/DIV
RMS
FF
and C
when the output voltage is
LT3060 Series
FF
REF/BYP
) from V
3060 F03
FF
, output voltage
FF
OUT
V
C
I
FB-DIVIDER
to achieve a
OUT
OUT
) from V
FF
to the ADJ
= 5V
= 10µF
must also
17
= 5µA
3060fa
OUT