LTC3736EGN-1#PBF Linear Technology, LTC3736EGN-1#PBF Datasheet - Page 11

• Manufacturer Part Number: LTC3736EGN-1#PBF
• Description: IC CTRLR SW SYNC DUAL 2PH 24SSOP
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3736EGN-1#PBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.6 ~ 9.8 V
• Current - Output: 1A
• Frequency - Switching: 450kHz ~ 580kHz
• Voltage - Input: 2.75 ~ 9.8 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

OPERATIO
operation enabled) with V
1A. Note the significant reduction in peak output noise
(>20dBm).
Short-Circuit Protection
When an output is shorted to ground (V
switching frequency of that controller is reduced to 1/5 of
the normal operating frequency. The other controller is
unaffected and maintains normal operation.
The short-circuit threshold on V
of 0.12V and a fraction of the voltage on the TRACK pin.
This also allows V
easily. Note that if V
(V
regulate V
connected to the TRACK pin.
OUT1
Figure 1a. Output Noise Spectrum of Conventional Buck
Switching Converter (LTC3736-1 with Spread Spectrum
Disabled) Showing Fundamental and Harmonic Frequencies
Figure 1c. Output Noise Spectrum of the LTC3736-1 Spread
Spectrum Buck Switching Converter. Note the Reduction in
Fundamental and Harmonic Peak Spectral Amplitude
Compared to Figure 1a.
= V
OUT2
FB1
–100
–110
–100
–110
–10
–20
–30
–40
–50
–60
–70
–80
–90
–10
–20
–30
–40
–50
–60
–70
–80
–90
0
0
= 0V), then the LTC3736-1 will try to
to 0V if a resistor divider on V
R
R
U
BW
BW
OUT2
= 3kHz
= 3kHz
6M
6M
(Refer to Functional Diagram)
to start up and track V
FREQUENCY (Hz)
FREQUENCY (Hz)
12M
12M
OUT1
IN
= 5V, V
18M
18M
is truly short-circuited
FB2
24M
24M
is based on the smaller
OUT
37361 F01a
37361 F01c
30M
30M
= 2.5V and I
FB
< 0.12V), the
OUT1
OUT1
OUT
more
is
=
Output Overvoltage Protection
As a further protection, the overvoltage comparator (OV)
guards against transient overshoots, as well as other more
serious conditions that may overvoltage the output. When
the feedback voltage on the V
above the reference voltage of 0.6V, the external P-chan-
nel MOSFET is turned off and the N-channel MOSFET is
turned on until the overvoltage is cleared.
Frequency Selection (FREQ Pin)
(Spread Spectrum Operation Disabled)
The switching frequency of the LTC3736-1 can be selected
using the FREQ pin when spread spectrum operation is
disabled (SSDIS = V
Figure 1b. Zoom-In of Fundamental Frequency of Conventional
Buck Switching Converter
Figure 1d. Zoom-In of Fundamental Frequency of the
LTC3736-1 Spread Spectrum Switching Converter. Note the
>20dB Reduction in Peak Amplitude and Spreading of the
Frequency Spectrum (Between Approximately 450kHz and
580kHz) Compared to Figure 1b.
–100
–110
–100
–110
–10
–20
–30
–40
–50
–60
–70
–80
–90
–10
–20
–30
–40
–50
–60
–70
–80
–90
410k
410k
R
R
BW
BW
= 30Hz
= 30Hz
450k
450k
IN
).
FREQUENCY (Hz)
FREQUENCY (Hz)
490k
490k
530k
530k
FB
570k
570k
pin has risen 13.33%
37361 F01b
37361 F01d
LTC3736-1
610k
610k
11
37361f