ZL2105ALNF Intersil, ZL2105ALNF Datasheet - Page 18

• 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

Configuration C: SYNC AUTO DETECT
When the SYNC pin is configured in auto detect mode
(CFG pin is left OPEN), the device will automatically
check for a clock signal on the SYNC pin after enable
is asserted.
- If a valid clock signal is present, the ZL2105’s
oscillator will then synchronize both frequency and
phase with the rising edge of the external clock signal.
The incoming clock signal must be in the range of 200
kHz to 2 MHz with a minimum duty cycle, and must
be stable when the EN pin is asserted. See Table 3 for a
complete list of performance requirements for the
incoming clock signal.
- If no incoming clock signal is present, the ZL2105
will configure the switching frequency according to the
state of the SYNC pin as listed in Table 13. In this
configuration, the SYNC pin is sampled only on start-
up and will not modify its switching frequency if the
SYNC pin is re-configured after start-up (unless the
power is recycled).
200kHz – 2MHz
200kHz – 2MHz
18
SYNC
ZL2105
N/C
A) SYNC = output
SYNC
ZL2105
Logic
high
OR
Figure 15. SYNC Pin Configurations.
Open
Logic
Logic
high
low
C) SYNC = Auto Detect
ZL2105
SYNC
200kHz – 2MHz
ZL2105
N/C
Table 13. Switching Frequency Selection
If the user wishes to run the ZL2105 at a frequency not
listed in Table 13, the switching frequency can be set
using an external resistor, R
SYNC and SGND using Table 14.
SYNC Pin
Resistor
B) SYNC = input
OPEN
HIGH
SYNC
LOW
OR
ZL2105
R
SYNC
SYNC
ZL2105
N/C
SYNC
See Table 14
, connected between
Frequency
200 kHz
400 kHz
1 MHz
March 30, 2011
FN6851.2