ZXLD1366_10 DIODES [Diodes Incorporated], ZXLD1366_10 Datasheet - Page 18

• Manufacturer Part Number: ZXLD1366_10
• Description: HIGH ACCURACY 1A, 60V LED DRIVER WITH INTERNAL SWITCH
• Manufacturer: DIODES [Diodes Incorporated]

Application Information
Setting nominal average output current with external resistor RS
The nominal average output current in the LED(s) is determined by the value of the external current sense resistor (RS)
connected between VIN and ISENSE and is given by:
I
The table below gives values of nominal average output current for several preferred values of current setting resistor (R
in the typical application circuit shown on page 1:
The above values assume that the ADJ pin is floating and at a nominal voltage of V
minimum allowed value of sense resistor under these conditions to maintain switch current below the specified maximum
value.
It is possible to use different values of R
Output current adjustment by external DC control voltage
The ADJ pin can be driven by an external dc voltage (V
below the nominal average value defined by R
The nominal average output current in this case is given by:
I
Note that 100% brightness setting corresponds to V
increased in proportion to prevent I
The input impedance of the ADJ pin is 50kΩ ±25% for voltages below V
+100mV.
ZXLD1366
Document number: DS31992 Rev. 5 - 2
OUTnom
OUTdc
R
0.20
0.27
0.56
S
(V)
= (V
= 0.2/R
ADJ
Nominal average output
current (mA)
1000
740
357
/1.25) x (0.2/R
S
[for R
S
≥ 0.2V]
DC
S
) [for 0.3< V
OUTdc
GND
+
S
exceeding 1A maximum.
if the ADJ pin is driven from an external voltage. (See next section).
S
.
ADJ
<2.5V]
ADJ
www.diodes.com
ADJ
ADJ
18 of 32
= V
), as shown, to adjust the output current to a value above or
REF
. When driving the ADJ pin above 1.25V, R
ZXLD1366
GND
REF
and 14.2kΩ ±25% for voltages above V
Diodes Incorporated
A Product Line of
REF
(=1.25V). Note that R
© Diodes Incorporated
S
ZXLD1366
= 0.2V is the
S
June 2010
must be
REF
S
)