LTC3736-1 Datasheet, PDF (4/28 Pages) Linear Technology – Dual 2-Phase, No RSENSE Synchronous Controller with Spread Spectrum

LTC3736-1
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25°C unless otherwise noted.
Efficiency and Power Lost vs
Load Current
10
FIGURE 13 CIRCUIT
V_IN = 5V
1
Load Step
(Spread Spectrum Enabled)
100
95
V_OUT
90 ^AC-COUPLED
100mV/DIV
85
Load Step
(Spread Spectrum Disabled)
V_OUT
AC-COUPLED
100mV/DIV
80
0.1
0.01
0.001
1
75
70
65
60
V_OUT = 2.5V 55
V_OUT = 1.8V ₅₀
10
100
1000 10000
LOAD CURRENT (mA)
I_L
2A/DIV
V_IN = 3.3V
100µs/DIV
V_OUT = 1.8V
I_LOAD = 300mA TO 3A
SSDIS = GND
FIGURE 15 CIRCUIT
I_L
2A/DIV
37361 G02
V_IN = 3.3V
100µs/DIV
V_OUT = 1.8V
I_LOAD = 300mA TO 3A
SSDIS = V_IN
FIGURE 15 CIRCUIT
37361 G03
37361 G01
Input Voltage Noise
(Spread Spectrum Disabled)
–10
FIGURE 13 CIRCUIT
–20 V_IN = 5V
–30
V_OUT = 2.5V
R_BW = 30Hz
–40 ^{SSDIS = V}IN
–50
–60
–70
–80
–90
–100
–110
410k 450k 490k 530k 570k 610k
FREQUENCY (Hz)
37361 G04
Input Voltage Noise
(Spread Spectrum Enabled)
–10
FIGURE 13 CIRCUIT
–20 V_IN = 5V
–30
V_OUT = 2.5V
R_BW = 30Hz
–40 ^{SSDIS = GND}
–50
–60
–70
–80
–90
–100
–110
410k 450k 490k 530k 570k 610k
FREQUENCY (Hz)
37361 G05
Tracking Start-Up with Internal
Soft-Start (C_SS = 0µF)
V_OUT1
2.5V
V_OUT2
1.8V
500mV/
DIV
V_IN = 5V
200µs/DIV
R_LOAD1 = R_LOAD2 = 1Ω
SSDIS = GND
FIGURE 15 CIRCUIT
37361 G06
Tracking Start-Up with External
Soft-Start (C_SS = 0.15µF)
V_OUT1
2.5V
V_OUT2
1.8V
500mV/
DIV
Output Voltage Ripple
V_IN = 5V
40ms/DIV
R_LOAD1 = R_LOAD2 = 1Ω
SSDIS = V_IN
FIGURE 15 CIRCUIT
37361 G07
1µs/DIV
FIGURE 15 CIRCUIT
ENVELOPE OF 100 SAMPLES
SSDIS = V_IN
CONSTANT
550kHz
OPERATION
50mV/DIV
AC-COUPLED
SSDIS = GND
SPREAD
SPECTRUM
37361 G20
Oscillator Frequency
vs Input Voltage
5
SSDIS = V_IN
4
3
2
1
0
–1
–2
–3
–4
–5
23 4 56 78
INPUT VOLTAGE (V)
9 10
37361 G08
37361f
4