TLD5085EJ Infineon Technologies, TLD5085EJ Datasheet - Page 7

• Manufacturer Part Number: TLD5085EJ
• Description: IC DC-DC CONV STP-DWN 1.8A DSO8
• Manufacturer: Infineon Technologies

Specifications of TLD5085EJ

• Constant Current: Yes
• Constant Voltage: Yes
• Topology: PWM, Step-Down (Buck), Switched Capacitor (Charge Pump)
• Number Of Outputs: 1
• Internal Driver: *
• Type - Primary: Automotive
• Frequency: 370kHz
• Voltage - Supply: 4.75 V ~ 45 V
• Voltage - Output: 0.6 V ~ 16 V
• Mounting Type: Surface Mount
• Package / Case: DSO-8
• Current - Output / Channel: 1.8A
• Internal Switch(s): *
• Efficiency: *
• Packages: PG-DSO-8
• Vs (min): 4.75 V
• Vs (max): 45.0 V
• Vq (max): -
• Iq (max): 1,800.0 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Lead Free Status / Rohs Status: Details

5
5.1
The gate of the power-switch is driven by the Gate driver which is supplied by the external capacitor connected to
pin BDS (Buck Driver Supply) using the bootstrap principle.
BDS is the supply pin for the integrated gate driver of the internal power-switch. The power-switch has to be in the
R
power dissipation. An integrated under voltage lockout function (BDS UV-Comparator) supervising the ’bootstrap’
capacitor voltage ensures that the device is always driven with a sufficient bootstrap voltage in order to prevent
from extensive heat up of the power-switch.
An integrated charge pump supports the gate driver in case of low input supply voltage, small differential voltage
between input supply and output voltage at low current and during startup. In order to minimize emission, the
charge pump is switched off if the input voltage is sufficient for supplying the bootstrap.
The soft start function generates a defined ramp of the reference voltage during the first 0.5 ms (typ.) after device
initialization and if the Device is autorestarting after a thermal shutdown. This function is disabled during the
dimming operation via the PWMI-pin.
Figure 3
Datasheet
COMP
DSon
FB
VS
region. If V
4
8
3
Soft Start
Buck Regulator
Description
Block Diagram Buck Regulator
Ramp
GND
2
=
V
GS
REF
=0.6V
is not high enough, the power-switch can not operate in the R
+
-
Feedback
Error Amp.
Ramp Generator
Overcurrent
Comp.
PWM
Comp.
PWMI
1
7
Sensor
Temp.
Clock
Logic
BDS
UV Comp.
Driver
Gate
Charger
Charge
Pump
BDS
DSON
region, which means high
Rev. 1.1, 2009-12-16
Buck Regulator
Power
Switch
TLD5085EJ
5
6
BDS
BUO