STOD03AS STMicroelectronics, STOD03AS Datasheet - Page 19

• Manufacturer Part Number: STOD03AS
• Description: Dual DC-DC converter for powering AMOLED displays
• Manufacturer: STMicroelectronics

Specifications of STOD03AS

• Typical Efficiency: 85%
• Temperature Range: -40 °C to 85 °C

STOD03AS
8.1.5
8.1.6
8.1.7
8.1.8
8.1.9
8.1.10
Enable pin
The device operates when the EN pin is set high. If the EN pin is set low, the device stops
switching, and all the internal blocks are turned off. In this condition the current drawn from
V
are in an OFF state so the load is electrically disconnected from the input, this avoids
unwanted current leakage from the input to the load.
When the EN is pulled high, the P1B switch is turned on for 100 µs. In normal operation,
during this time, apart of a small drop due to parasitic resistance, V
If, after this 100 µs, V
pulse is applied to the EN. This mechanism avoids the STOD03AS starting if a short-circuit
is present on V
Soft-start and inrush current limiting
After the EN pin is pulled high, or after a suitable voltage is applied to V
device initiates the startup phase.
As a first step, the C
limiting technique in order to keep the charge current below 400 mA. This avoids the battery
overloading during startup.
After V
procedure for the step-up is started. After around 2 ms the soft-start for the inverting is
started. The positive and negative voltages are under regulation at around 6 ms after the
EN pin is asserted high.
Undervoltage lockout
The undervoltage lockout function avoids improper operation of the STOD03AS when the
input voltage is not high enough. When the input voltage is below the UVLO threshold the
device is in shutdown mode. The hysteresis of 50mV avoids unstable operation when the
input voltage is close to the UVLO threshold.
Overtemperature protection
An internal temperature sensor continuously monitors the IC junction temperature. If the IC
temperature exceeds 140 °C, typical, the device stops operating. As soon as the
temperature falls below 125 °C, typical, normal operation is restored.
Short-circuit protection
When short-circuit occurs, the device is able to detect the voltage difference between V
and V
output stages of the device are turned off. This status is maintained, avoiding current flowing
to the load. A new ENABLE transition is needed to restart the device. During startup the
short-circuit protection is active.
Fast discharge
When ENABLE turns from high to low level, the device goes into shutdown mode and LX1
and LX2 stop switching. Then, the discharge switch between V
between V
output voltage. When the output voltages are discharged to 0 V, the switches turn off and the
outputs are high impedance.
INP
/V
MID
INA
MID
. Overshoots on LX1 are limited, decreasing the inductor current. After that, the
is below 1 µA in the whole temperature range. In addition, the internal switches
O2
reaches the V
and GND turn on and discharge the positive output voltage and negative
MID
.
MID
MID
capacitor is charged and the P1B switch implements a current
INP
stays below V
voltage level, the P1B switch is fully turned on and the soft-start
Doc ID 022614 Rev 1
IN
, the P1B is turned off and stays off until a new
MID
and V
MID
Detailed description
INP
reaches V
IN
, V
and the switch
INA
and EN, the
IN
.
19/24
IN