DRV110_15 Datasheet, PDF (7/24 Pages) Texas Instruments – Power-Saving Solenoid Controller

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7 Detailed Description
DRV110
SLVSBA8B – MARCH 2012 – REVISED JULY 2015
7.1 Overview
The DRV110 device provides a PWM current controller for use with solenoids. The device provides a quick ramp
to a high peak current value in order to ensure opening of the valve or relay. The peak current is held for a
programmable time and then released to a lower value to maintain the open state of the valve or relay while
reducing the total current consumption. Peak current duration, peak current amount, hold current amount (in the
14-pin package), and PWM frequency can all be controlled by external components or used at default levels by
omitting these components (except peak current duration). Enable and disable of the switch is controlled by the
EN pin. The DRV110 also features a wide VIN range with an internal bypass regulator to maintain VIN at an
acceptable level. Finally, the 14-pin package features an open-drain pull-down path on the STATUS pin which is
enabled as long as undervoltage lockout or thermal shutdown has not triggered.
7.2 Functional Block Diagram
R_OSC
OSC
<STATUS>¹
R_S
VIN
V_S
C₁
EN
1 uA
LDO
UVLO
Thermal
Shutdown
OSC
500 kW
PWM_CLK
PWM
Control
V_S
V_IN
OUT
L_S
D₁
M₁
100 mV
REF
V_PEAK
V_HOLD
V_REF
Sense
1_{Available only in the 14-pin package}
7.3 Feature Description
The DRV110 controls the current through the solenoid as shown in Figure 2. Activation starts when EN pin
voltage is pulled high either by an external driver or internal pullup. In the beginning of activation, DRV110 allows
the load current to ramp up to the peak value I_PEAK and it regulates it at the peak value for the time, t_KEEP, before
reducing it to I_HOLD. The load current is regulated at the hold value as long as the EN pin is kept high. The initial
current ramp-up time depends on the inductance and resistance of the solenoid. Once EN pin is driven to GND,
DRV110 allows the solenoid current to decay to zero.
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