ssl3250a NXP Semiconductors, ssl3250a Datasheet - Page 8

• Manufacturer Part Number: ssl3250a
• Description: Photo ?ash Dual Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SSL3250A_2
Product data sheet
default current is equal to connecting an external current set resistor of 50 k . Entering
Torch mode in Direct enable mode can be done using the EN1 and EN2 pins. The LED
will stay on in Torch mode for as long as the enable pins are set to Torch mode.
When not using an external resistor, the R_TR pin can be left unconnected, but it is
preferably connected to VIN. Never connect the R_TR pin to GND since it will cause
unnecessary reference currents to flow to GND.
Figure 6
illustrates the Torch mode current setting equation for the Direct enable mode.
I
LED
Fig 6.
Fig 7.
=
I
LED
50 k
---------------
R
illustrates the Torch mode current setting equation for I
I
Torch mode LED current in I
Torch mode LED current in Direct enable mode
LED
R_TR
(mA)
200
150
100
50
0
(mA)
250
200
150
125
100
0
50
0
125 mA
1
Rev. 02 — 21 April 2009
125
3
Torch current using direct control mode
Torch current using I
2
C mode
5
50
2
C mode
7
Photo flash dual LED driver
9
2
C, while
SSL3250A
31.3
© NXP B.V. 2009. All rights reserved.
Figure 7
11
value (k )
014aaa365
Register
014aaa364
Register
value
8 of 26
(2)