TS3410CX5RF TSC [Taiwan Semiconductor Company, Ltd], TS3410CX5RF Datasheet - Page 4

• Manufacturer Part Number: TS3410CX5RF
• Description: 1A / 1.5MHz Synchronous Buck Converter
• Manufacturer: TSC [Taiwan Semiconductor Company, Ltd]

Function Description (Continue)
Maximum Load Current
The TS3410 will operate with input supply voltage as low as 2.5V, however, the maximum load current decreases at
lower input due to large IR drop on the main switch and synchronous rectifier. The slope compensation signal reduces
the peak inductor current as a function of the duty cycle to prevent sub-harmonic oscillations at duty cycles greater than
50%. Conversely the current limit increases as the duty cycle decreases.
Application Information
Setting the Output Voltage
Application circuit item shows the basic application circuit with TS3410 adjustable output version. The external resistor
sets the output voltage according to the following equation:
Inductor Selection
For most designs, the TS3410 operates with inductors of 1µH to 4.7µH. Low inductance values are physically smaller
but require faster switching, which results in some efficiency loss. The inductor value can be derived from the following
equation:
Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high
ripple currents. Choose inductor ripple current approximately 35% of the maximum load current 1A, ∆IL=350mA.
For output voltages above 2.0V, when light-load efficiency is important, the minimum recommended inductor is 2.2µH.
For optimum voltage-positioning load transients, choose an inductor with DC series resistance in the 50mΩ to 150mΩ
range. For higher efficiency at heavy loads (above 200mA), or minimal load regulation (but some transient overshoot),
the resistance should be kept below 100mΩ. The DC current rating of the inductor should be at least equal to the
maximum load current plus half the ripple current to prevent core saturation (1A+170mA).
Input Capacitor Selection
The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input
capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency
switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used.
Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small
temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient.
Table 2: Inductor Select for Output Voltage Setting (Vcc-3.6V)
Note: Part Type MH or M (www.we-online.com)
Part Number
Table 1: Resistor Select for Output Voltage Setting
WE-TPC
Inductor
VOUT
VOUT
1.2V
1.5V
1.8V
2.5V
1A / 1.5MHz Synchronous Buck Converter
7440430027
2.2uH
1.2V
4/7
300K
300K
300K
300K
R2
7440430027
2.2uH
1.5V
300K
450K
600K
950K
R1
7440430027
2.2uH
1.8V
TS3410
7440430022
Version: A08
2.2uH
2.5V