MC34844EP Datasheet, PDF (34/62 Pages) Freescale Semiconductor, Inc – 10 Channel LED Backlight Driver with Integrated Power Supply

PIN CONNECTIONS
MC34844A
PIN CONNECTIONS
EP = Exposed Pad
32 31 30 29 28 27 26 25
VIN 1
24 CK
PGNDB 2
SWB 3
SWA 4
PGNDA 5
A0/SEN 6
TRANSPARENT
TOP VIEW
QFN - EP
5MM X 5MM
32 LEAD
EP GND
23 VDC3
22 SLOPE
21 NIN
20 PIN
19 ISET
EN 7
18 FAIL
IO 8
17 I9
9 10 11 12 13 14 15 16
I1 I2 I3 I4 I5 I6 I7 I8
Figure 24. 34844A Pin Connections
Table 9. 34844A Pin Definitions
A functional description of each pin can be found in the Functional Pin Description section beginning on page 42.
Pin Number Pin Name Pin Function Formal Name
Definition
1
2
3
4
5
6
7
8 - 17
18
19
20
21
22
23
24
25
VIN
PGNDB
SWB
SWA
PGNDA
A0/SEN
EN
I0-I9
FAIL
ISET
PIN
NIN
SLOPE
VDC3
CK
PWM
Power
Input voltage
Input supply
Power
Power Ground
Power ground
Input
Switch node B
Boost switch connection B
Input
Switch node A
Boost switch connection A
Power
Power Ground
Power ground
Input
Device Select
Address select, device select pin or OVP HW control
Input
Enable
Enable pin (active high, internal pull-up)
Input
LED Channel
LED string connections
Open Drain
Fault detection
Fault detected pin (open drain):
No Failure = Low-impedance
Failure = High-impedance
Passive
Current set
LED current setting resistor
Input
Positive current scale Positive input analog current control
Input ^{Negative current scale Negative input analog current control}
Passive
Boost Slope
Boost slope compensation Setting resistor
Output
Internal Regulator 3 Decoupling capacitor for internal phase locked loop power
Input/Output
Clock signal
Clock synchronization pin (input for M/~S = low - internal pull-up, output
for M/~S = high)
Input
External PWM
External PWM input (internal pull-down)
34844A
34
Analog Integrated Circuit Device Data
Freescale Semiconductor