ZL2106ALCFTK Intersil, ZL2106ALCFTK Datasheet - Page 16

• Manufacturer Part Number: ZL2106ALCFTK
• Description: 6A Digital DC-DC Converter W/ DDC - TR1K
• Manufacturer: Intersil
• Series: -r
• Type: Step-Down (Buck), PWM - Voltage Moder

Specifications of ZL2106ALCFTK

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.54 V ~ 5.5 V
• Current - Output: 6A
• Frequency - Switching: 200kHz ~ 1MHz
• Voltage - Input: 4.5 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 36-VFQFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

If the user wishes to run the ZL2106 at a frequency not listed in
Table 8, the switching frequency can be set using an external
resistor, R
The switching frequency can also be set to any value between
200kHz and 1MHz using the I
frequencies are defined by f
N is 8 ≤ N ≤ 40. See Application Note AN2033 for details.
If a value other than f
command, the internal circuitry will select the valid switching
frequency value that is closest to the entered value. For example,
if 810kHz is entered, the device will select 800kHz (N=10).
Note: The switching frequency read back using the appropriate
PMBus command will differ slightly from the selected value in
Table 9. The difference is due to hardware quantization.
When multiple Zilker Labs devices are used together, connecting
the SYNC pins together will force all devices to synchronize with
each other. The CFG pin of one device must set its SYNC pin as an
output and the remaining devices must have their SYNC pins set
as an input or as auto detect.
Note: Precise ramp timing mode must be disabled to use SYNC
clock auto detect.
SYNC
SYNC PIN
Resistor
TABLE 8. SWITCHING FREQUENCY SELECTION
OPEN
HIGH
LOW
, connected between SYNC and SGND using Table 9.
R
12.1
13.3
14.7
16.2
19.6
21.5
23.7
26.1
28.7
31.6
34.8
38.3
42.2
46.4
(kΩ)
17.8
SYNC
10
11
TABLE 9. R
SW
= 8MHz/N is entered using a PMBus
SYNC
SW
2
16
C/SMBus interface. The available
= 8MHz/N, where whole number
RESISTOR VALUES
FREQUENCY
See Table 9
200kHz
400kHz
1MHz
1000
(kHz)
F
200
222
242
267
296
320
364
400
421
471
533
571
615
667
727
889
SW
ZL2106
Component Selection
The ZL2106 is a synchronous buck converter with integrated
MOSFETs that uses an external inductor and capacitors to
perform the power conversion process. The proper selection of
the external components is critical for optimized performance.
To select the appropriate external components for the desired
performance goals, the power supply requirements listed in
Table 10 must be defined.
DESIGN GOAL TRADE-OFFS
The design of the buck power stage requires several compromises
among size, efficiency and cost. The inductor core loss increases
with frequency, so there is a trade-off between a small output filter
made possible by a higher switching frequency and getting better
power supply efficiency. Size can be decreased by increasing the
switching frequency at the expense of efficiency. Cost can be
minimized by using through-hole inductors and capacitors; however
these components are physically large.
To start the design, select a frequency based on Table 11. This
frequency is a starting point and may be adjusted as the design
progresses.
INDUCTOR SELECTION
The output inductor selection process must include several
trade-offs. A high inductance value will result in a low ripple
current (I
a low output ripple voltage, but may also compromise output
transient load performance. Therefore, a balance must be struck
Input Voltage (V
Output Voltage (V
Output Current (I
Output Voltage Ripple (V
Output Load Step (I
Output Load Step Rate
Output Deviation Due to
Load Step
Maximum PCB Temp.
Desired Efficiency
Other Considerations
FREQUENCY RANGE
200kHz to 400kHz
400kHz to 800kHz
800kHz to 1MHz
PARAMETER
opp
TABLE 11. CIRCUIT DESIGN CONSIDERATIONS
), which will reduce output capacitance and produce
TABLE 10. POWER SUPPLY REQUIREMENTS
IN
OUT
OUT
)
ostep
)
)
)
orip
)
4.5V to 14.0V
< 3% of V
0.6V to 5.0V
0A to 6A
+120°C
RANGE
EFFICIENCY
< I
Moderate
-
-
-
-
Highest
Lower
o
OUT
Optimize for small size
EXAMPLE VALUE
±1% of V
±3% of V
±25% of I
2.5A/µs
+85°C
CIRCUIT SIZE
3.3V
85%
12V
4A
Smallest
Smaller
Larger
OUT
OUT
FN6852.4
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