ZL2105ALNF Intersil, ZL2105ALNF Datasheet - Page 15

• Manufacturer Part Number: ZL2105ALNF
• Description: IC DGTL DC-DC CTRLR 3A 36QFN
• Manufacturer: Intersil
• Type: Step-Down (Buck), PWM - Voltage Moder

Specifications of ZL2105ALNF

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.6 V ~ 5.5 V
• Current - Output: 3A
• Frequency - Switching: 200kHz ~ 2MHz
• Voltage - Input: 4.5 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: *
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5.5 Output voltage Selection
The output voltage may be set to any voltage between
0.6 V and 5.0 V provided that the input voltage is
higher than the desired output voltage by an amount
sufficient to prevent the device from exceeding its
maximum duty cycle specification. Using the pin-strap
method, V
voltages as shown in Table 6.
Table 6. Pin-strap Output Voltage Settings
The resistor setting method can be used to set the
output voltage to levels not available in Table 6.
Resistors R0 and R1 are selected to produce a specific
voltage between 0.6 V and 5.0 V in 10 mV steps.
Resistor R1 provides a coarse setting and resistor R0
provides a fine adjustment, thus eliminating the
additional errors associated with using two 1%
resistors (this typically adds 1.4% error).
To set V
calculate an index value and then use
the resistor that corresponds to the calculated index
value as follows:
1. Calculate Index1:
2. Round the result down to the nearest whole
3. Select the value of R1 f
4. Calculate Index0:
5. Select the value of R0 from
V1
number.
Index1 rounded value from step 2.
Index0 = 100 x V
Index0 value from step 4.
Index1 = 4 x V
OUT
OPEN
HIGH
LOW
OUT
using resistors, follow the steps below to
can be set to any of nine standard
OUT
15
LOW
0.6 V
1.2 V
2.5 V
OUT
(V
– (25 x Index1)
OUT
rom
in 10 mV steps)
OPEN
0.8 V
1.5 V
3.3 V
Table 7
V0
Table 7
Table 7
using the
using the
to select
HIGH
1.0 V
1.8 V
5.0 V
ZL2105
Table 7. Resistors for Setting Output Voltage
Example: For V
The output voltage may also be set to any value
between 0.6 V and 5.5 V using the I
Application Note AN2013 for details.
Index
Figure 13. Output Voltage Resistor Setting
10
11
12
0
1
2
3
4
5
6
7
8
9
Index1 = 4 x 1.33 V = 5.32;
From
Index0 = (100 x 1.33 V) – (25 x 5) = 8;
From
21.5k
R0
Table 7
Table 7
ZL2105
OUT
R0 or R1
12.1 k
13.3 k
14.7 k
16.2 k
17.8 k
19.6 k
21.5 k
23.7 k
26.1 k
28.7 k
31.6 k
10 k
11 k
= 1.33 V,
16.2k
, R1 = 16.2 kΩ
, R0 = 21.5 kΩ
VDDS
VDDP
R1
SW
Example
V
IN
Index
13
14
15
16
17
18
19
20
21
22
23
24
2
1.33V
C interface. See
March 30, 2011
V
OUT
FN6851.2
R0 or R1
34.8 k
38.3 k
42.2 k
46.4 k
51.1 k
56.2 k
61.9 k
68.1 k
82.5 k
90.9 k
100 k
75 k