zl2005 Intersil Corporation, zl2005 Datasheet - Page 16

• Manufacturer Part Number: zl2005
• Description: Digital-dc? Integrated Power Management And Conversion Ic
• Manufacturer: Intersil Corporation

To set V
calculate an index value and then use Table 7 to select
the resistor that corresponds to the calculated index
value as follows:
1. Calculate Index1:
2. Round the result down to the nearest whole num-
3. Select the value for R1 from Table 7 using the
4. Calculate Index0 using equation
5. Select the value for R0 from Table 7 using Index0
Table 7. Resistors for Setting Output Voltage
Example:
For V
Index1 = 4 x 1.33V = 5.32 (5);
From Table 7, using Index = 5
R1 = 16.2 kΩ
Index0 = (100 x 1.33V) - (25 x 5) = 8;
From Table 7; R0 = 21.5 kΩ
Index
10
11
12
Index1 = 4 x V
ber.
Index1 rounded value from step 2.
from step 4.
0
1
2
3
4
5
6
7
8
9
Index0 = 100 x V
OUT
OUT
= 1.33V:
R0 or R1
12.1 kΩ
13.3 kΩ
14.7 kΩ
16.2 kΩ
17.8 kΩ
19.6 kΩ
21.5 kΩ
23.7 kΩ
26.1 kΩ
28.7 kΩ
31.6 kΩ
using resistors, follow the steps below to
10 kΩ
11 kΩ
OUT
OUT
16
- 25 x
Index
13
14
15
16
17
18
19
20
21
22
23
24
Index1...
R0 or R1
34.8 kΩ
38.3 kΩ
42.2 kΩ
46.4 kΩ
51.1 kΩ
56.2 kΩ
61.9 kΩ
68.1 kΩ
82.5 kΩ
90.9 kΩ
100 kΩ
75 kΩ
ZL2005
The output voltage may also be set to any value
between 0.6V and 5.5V using the I
face. See Application Note AN13 for details.
5.4 Start-up Procedure
The ZL2005 follows a specific internal start-up proce-
dure after power is applied to the VDD pin. Table 8
describes the start-up sequence.
If the device is to be synchronized to an external clock
source, the clock must be stable prior to asserting the
EN pin. The device requires approximately 10-20 ms
to check for specific values stored in its internal mem-
ory. If the user has stored values in memory, those val-
ues will be loaded. The device will then check the
status of all multi-mode pins and load the values asso-
ciated with the pin settings.
Once this process is completed, the device is ready to
accept commands via the I
device is ready to be enabled. Once enabled, the
device requires approximately 6 ms before its output
voltage may be allowed to start its ramp-up process. If
a soft start delay period less than 6 ms has been con-
figured (using the DLY (0,1) pins), the device will
default to a 6 ms delay period. If a delay period of 6
ms or higher is configured, the device will wait for the
configured delay period before starting to ramp its out-
put.
After the delay period has expired, the output will
begin to ramp towards its target voltage according to
the pre-configured soft-start ramp time (using the SS
(0,1) pins).
Figure 10. Output Voltage Resistor Setting
Example
2
C/SMBus interface and the
2
C/SMBus inter-
February 18, 2009
FN6848.0